diff --git a/Cargo.toml b/Cargo.toml
index 9d0678ac..4c734f4f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,22 +9,22 @@ edition = "2021"
 [features]
 # when "debug" feature is turned on, that of the following crates will also be turned on.
 debug = [
-    "common/debug",
-    "parser/debug",
-    "compiler/debug",
-    #"vm/debug"
+    "erg_common/debug",
+    "erg_parser/debug",
+    "erg_compiler/debug",
+    #"erg_vm/debug"
 ]
 japanese = [
-    "common/japanese",
-    "parser/japanese",
-    "compiler/japanese",
-    #"vm/japanese"
+    "erg_common/japanese",
+    "erg_parser/japanese",
+    "erg_compiler/japanese",
+    #"erg_vm/japanese"
 ]
 
 [dependencies]
-common = { path = "./src/common" }
-parser = { path = "./src/compiler/parser" }
-compiler = { path = "./src/compiler" }
+erg_common = { path = "./src/erg_common" }
+erg_parser = { path = "./src/erg_compiler/erg_parser" }
+erg_compiler = { path = "./src/erg_compiler" }
 # vm = { path = "./src/vm" }
 
 # [workspace]
diff --git a/src/dummy.rs b/src/dummy.rs
index 4e144603..4f36e7c7 100644
--- a/src/dummy.rs
+++ b/src/dummy.rs
@@ -1,10 +1,10 @@
-use common::config::{ErgConfig, Input, SEMVER, BUILD_INFO};
-use common::python_util::eval_pyc;
-use common::str::Str;
-use common::traits::Runnable;
+use erg_common::config::{ErgConfig, Input, SEMVER, BUILD_INFO};
+use erg_common::python_util::eval_pyc;
+use erg_common::str::Str;
+use erg_common::traits::Runnable;
 
-use compiler::Compiler;
-use compiler::error::{CompileError, CompileErrors};
+use erg_compiler::Compiler;
+use erg_compiler::error::{CompileError, CompileErrors};
 
 #[derive(Debug)]
 pub struct DummyVM {
diff --git a/src/common/Cargo.toml b/src/erg_common/Cargo.toml
similarity index 94%
rename from src/common/Cargo.toml
rename to src/erg_common/Cargo.toml
index 06f92203..d04d5122 100644
--- a/src/common/Cargo.toml
+++ b/src/erg_common/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "common"
+name = "erg_common"
 version = "0.1.0"
 description = "A common components library of Erg"
 authors = ["Shunsuke Shibayama <sbym1346@gmail.com>"]
diff --git a/src/common/build.rs b/src/erg_common/build.rs
similarity index 100%
rename from src/common/build.rs
rename to src/erg_common/build.rs
diff --git a/src/common/cache.rs b/src/erg_common/cache.rs
similarity index 100%
rename from src/common/cache.rs
rename to src/erg_common/cache.rs
diff --git a/src/common/codeobj.rs b/src/erg_common/codeobj.rs
similarity index 100%
rename from src/common/codeobj.rs
rename to src/erg_common/codeobj.rs
diff --git a/src/common/color.rs b/src/erg_common/color.rs
similarity index 100%
rename from src/common/color.rs
rename to src/erg_common/color.rs
diff --git a/src/common/combinations.rs b/src/erg_common/combinations.rs
similarity index 100%
rename from src/common/combinations.rs
rename to src/erg_common/combinations.rs
diff --git a/src/common/config.rs b/src/erg_common/config.rs
similarity index 100%
rename from src/common/config.rs
rename to src/erg_common/config.rs
diff --git a/src/common/datetime.rs b/src/erg_common/datetime.rs
similarity index 100%
rename from src/common/datetime.rs
rename to src/erg_common/datetime.rs
diff --git a/src/common/deserialize.rs b/src/erg_common/deserialize.rs
similarity index 100%
rename from src/common/deserialize.rs
rename to src/erg_common/deserialize.rs
diff --git a/src/common/dict.rs b/src/erg_common/dict.rs
similarity index 100%
rename from src/common/dict.rs
rename to src/erg_common/dict.rs
diff --git a/src/common/error.rs b/src/erg_common/error.rs
similarity index 100%
rename from src/common/error.rs
rename to src/erg_common/error.rs
diff --git a/src/common/fxhash.rs b/src/erg_common/fxhash.rs
similarity index 100%
rename from src/common/fxhash.rs
rename to src/erg_common/fxhash.rs
diff --git a/src/common/lazy.rs b/src/erg_common/lazy.rs
similarity index 100%
rename from src/common/lazy.rs
rename to src/erg_common/lazy.rs
diff --git a/src/common/lazy_buffer.rs b/src/erg_common/lazy_buffer.rs
similarity index 100%
rename from src/common/lazy_buffer.rs
rename to src/erg_common/lazy_buffer.rs
diff --git a/src/common/levenshtein.rs b/src/erg_common/levenshtein.rs
similarity index 100%
rename from src/common/levenshtein.rs
rename to src/erg_common/levenshtein.rs
diff --git a/src/common/lib.rs b/src/erg_common/lib.rs
similarity index 100%
rename from src/common/lib.rs
rename to src/erg_common/lib.rs
diff --git a/src/common/macros.rs b/src/erg_common/macros.rs
similarity index 95%
rename from src/common/macros.rs
rename to src/erg_common/macros.rs
index d94cedb1..84a3d14b 100644
--- a/src/common/macros.rs
+++ b/src/erg_common/macros.rs
@@ -70,14 +70,14 @@ macro_rules! switch_lang {
 #[macro_export]
 macro_rules! enum_unwrap {
     ($ex: expr, $Enum: path $(,)*) => {{
-        if let $Enum(res) = $ex { res } else { common::switch_unreachable!() }
+        if let $Enum(res) = $ex { res } else { erg_common::switch_unreachable!() }
     }};
     ($ex: expr, $Enum: path :( $Cons: path :(_) ) $(,)*) => {{
-        if let $Enum($Cons(res)) = $ex { res } else { common::switch_unreachable!() }
+        if let $Enum($Cons(res)) = $ex { res } else { erg_common::switch_unreachable!() }
     }};
     // X::A{a, b}
     ($ex: expr, $Enum: path {$($fields: ident $(,)*)*}) => {{
-        if let $Enum{$($fields,)*} = $ex { ($($fields,)*) } else { common::switch_unreachable!() }
+        if let $Enum{$($fields,)*} = $ex { ($($fields,)*) } else { erg_common::switch_unreachable!() }
     }};
 }
 
@@ -187,10 +187,10 @@ macro_rules! power_assert {
 #[macro_export]
 macro_rules! debug_power_assert {
     ($l: expr, $op: tt, $r: expr) => {
-        if cfg!(debug_assertions) { common::power_assert!($l, $op, $r) }
+        if cfg!(debug_assertions) { erg_common::power_assert!($l, $op, $r) }
     };
     ($ex: expr) => {
-        if cfg!(debug_assertions) { common::power_assert!($ex) }
+        if cfg!(debug_assertions) { erg_common::power_assert!($ex) }
     };
 }
 
diff --git a/src/common/opcode.rs b/src/erg_common/opcode.rs
similarity index 100%
rename from src/common/opcode.rs
rename to src/erg_common/opcode.rs
diff --git a/src/common/python_util.rs b/src/erg_common/python_util.rs
similarity index 100%
rename from src/common/python_util.rs
rename to src/erg_common/python_util.rs
diff --git a/src/common/rccell.rs b/src/erg_common/rccell.rs
similarity index 100%
rename from src/common/rccell.rs
rename to src/erg_common/rccell.rs
diff --git a/src/common/serialize.rs b/src/erg_common/serialize.rs
similarity index 100%
rename from src/common/serialize.rs
rename to src/erg_common/serialize.rs
diff --git a/src/common/set.rs b/src/erg_common/set.rs
similarity index 100%
rename from src/common/set.rs
rename to src/erg_common/set.rs
diff --git a/src/common/stdin.rs b/src/erg_common/stdin.rs
similarity index 100%
rename from src/common/stdin.rs
rename to src/erg_common/stdin.rs
diff --git a/src/common/str.rs b/src/erg_common/str.rs
similarity index 100%
rename from src/common/str.rs
rename to src/erg_common/str.rs
diff --git a/src/common/traits.rs b/src/erg_common/traits.rs
similarity index 94%
rename from src/common/traits.rs
rename to src/erg_common/traits.rs
index d798536f..0df0ba25 100644
--- a/src/common/traits.rs
+++ b/src/erg_common/traits.rs
@@ -100,7 +100,7 @@ macro_rules! impl_displayable_stream_for_wrapper {
 
         impl std::fmt::Display for $Strc {
             fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> fmt::Result {
-                write!(f, "[{}]", common::fmt_iter(self.iter()).replace("\n", "\\n"))
+                write!(f, "[{}]", erg_common::fmt_iter(self.iter()).replace("\n", "\\n"))
             }
         }
 
@@ -111,10 +111,10 @@ macro_rules! impl_displayable_stream_for_wrapper {
 
         impl std::ops::Index<usize> for $Strc {
             type Output = $Inner;
-            fn index(&self, idx: usize) -> &Self::Output { common::traits::Stream::get(self, idx).unwrap() }
+            fn index(&self, idx: usize) -> &Self::Output { erg_common::traits::Stream::get(self, idx).unwrap() }
         }
 
-        impl common::traits::Stream<$Inner> for $Strc {
+        impl erg_common::traits::Stream<$Inner> for $Strc {
             #[inline]
             fn payload(self) -> Vec<$Inner> { self.0 }
             #[inline]
@@ -142,10 +142,10 @@ macro_rules! impl_stream_for_wrapper {
 
         impl std::ops::Index<usize> for $Strc {
             type Output = $Inner;
-            fn index(&self, idx: usize) -> &Self::Output { common::traits::Stream::get(self, idx).unwrap() }
+            fn index(&self, idx: usize) -> &Self::Output { erg_common::traits::Stream::get(self, idx).unwrap() }
         }
 
-        impl common::traits::Stream<$Inner> for $Strc {
+        impl erg_common::traits::Stream<$Inner> for $Strc {
             #[inline]
             fn payload(self) -> Vec<$Inner> { self.0 }
             #[inline]
@@ -159,7 +159,7 @@ macro_rules! impl_stream_for_wrapper {
 #[macro_export]
 macro_rules! impl_stream {
     ($Strc: ident, $Inner: ident, $field: ident) => {
-        impl common::traits::Stream<$Inner> for $Strc {
+        impl erg_common::traits::Stream<$Inner> for $Strc {
             #[inline]
             fn payload(self) -> Vec<$Inner> { self.$field }
             #[inline]
@@ -170,7 +170,7 @@ macro_rules! impl_stream {
 
         impl std::ops::Index<usize> for $Strc {
             type Output = $Inner;
-            fn index(&self, idx: usize) -> &Self::Output { common::traits::Stream::get(self, idx).unwrap() }
+            fn index(&self, idx: usize) -> &Self::Output { erg_common::traits::Stream::get(self, idx).unwrap() }
         }
     }
 }
@@ -320,8 +320,8 @@ pub trait Locational {
 #[macro_export]
 macro_rules! impl_locational_for_enum {
     ($Enum: ident; $($Variant: ident $(,)?)*) => {
-        impl common::traits::Locational for $Enum {
-            fn loc(&self) -> common::error::Location {
+        impl erg_common::traits::Locational for $Enum {
+            fn loc(&self) -> erg_common::error::Location {
                 match self {
                     $($Enum::$Variant(v) => v.loc(),)*
                 }
@@ -396,7 +396,7 @@ pub trait HasType {
 #[macro_export]
 macro_rules! impl_t {
     ($T: ty, $t: ident) => {
-        impl common::traits::HasType for $T {
+        impl erg_common::traits::HasType for $T {
             #[inline]
             fn ref_t(&self) -> &common::ty::Type { &common::ty::Type::$t }
         }
diff --git a/src/common/tsort.rs b/src/erg_common/tsort.rs
similarity index 100%
rename from src/common/tsort.rs
rename to src/erg_common/tsort.rs
diff --git a/src/common/ty.rs b/src/erg_common/ty.rs
similarity index 100%
rename from src/common/ty.rs
rename to src/erg_common/ty.rs
diff --git a/src/common/value.rs b/src/erg_common/value.rs
similarity index 100%
rename from src/common/value.rs
rename to src/erg_common/value.rs
diff --git a/src/compiler/.gitignore b/src/erg_compiler/.gitignore
similarity index 100%
rename from src/compiler/.gitignore
rename to src/erg_compiler/.gitignore
diff --git a/src/compiler/Cargo.toml b/src/erg_compiler/Cargo.toml
similarity index 61%
rename from src/compiler/Cargo.toml
rename to src/erg_compiler/Cargo.toml
index ccd2a498..0ce09a4e 100644
--- a/src/compiler/Cargo.toml
+++ b/src/erg_compiler/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "compiler"
+name = "erg_compiler"
 version = "0.1.0"
 description = "Centimetre: the Erg compiler"
 authors = ["Shunsuke Shibayama <sbym1346@gmail.com>"]
@@ -8,12 +8,12 @@ edition = "2021"
 
 [features]
 # when "debug" feature is turned on, that of parser will also be turned on.
-debug = [ "common/debug", "parser/debug" ]
-japanese = [ "common/japanese", "parser/japanese" ]
+debug = [ "erg_common/debug", "erg_parser/debug" ]
+japanese = [ "erg_common/japanese", "erg_parser/japanese" ]
 
 [dependencies]
-common = { path = "../common" }
-parser = { path = "parser" }
+erg_common = { path = "../erg_common" }
+erg_parser = { path = "erg_parser" }
 
 [lib]
 path = "lib.rs"
diff --git a/src/compiler/README.md b/src/erg_compiler/README.md
similarity index 100%
rename from src/compiler/README.md
rename to src/erg_compiler/README.md
diff --git a/src/compiler/codegen.rs b/src/erg_compiler/codegen.rs
similarity index 98%
rename from src/compiler/codegen.rs
rename to src/erg_compiler/codegen.rs
index 9a9e6a14..41f3e84a 100644
--- a/src/compiler/codegen.rs
+++ b/src/erg_compiler/codegen.rs
@@ -4,21 +4,21 @@
 use std::fmt;
 use std::process;
 
-use common::Str;
-use common::cache::Cache;
-use common::{fn_name_full, enum_unwrap, switch_unreachable, debug_power_assert, log, impl_stream_for_wrapper};
-use common::codeobj::{CodeObj, CodeObjFlags};
-use common::color::{GREEN, RESET};
-use common::config::{ErgConfig, Input};
-use common::error::{Location, MultiErrorDisplay};
-use common::value::ValueObj;
-use common::opcode::Opcode;
+use erg_common::Str;
+use erg_common::cache::Cache;
+use erg_common::{fn_name_full, enum_unwrap, switch_unreachable, debug_power_assert, log, impl_stream_for_wrapper};
+use erg_common::codeobj::{CodeObj, CodeObjFlags};
+use erg_common::color::{GREEN, RESET};
+use erg_common::config::{ErgConfig, Input};
+use erg_common::error::{Location, MultiErrorDisplay};
+use erg_common::value::ValueObj;
+use erg_common::opcode::Opcode;
 use Opcode::*;
-use common::traits::{HasType, Locational, Stream};
-use common::ty::{TypeCode, TypePair};
+use erg_common::traits::{HasType, Locational, Stream};
+use erg_common::ty::{TypeCode, TypePair};
 
-use parser::token::{Token, TokenKind, TokenCategory};
-use parser::ast::{VarPattern, ParamPattern, Params};
+use erg_parser::token::{Token, TokenKind, TokenCategory};
+use erg_parser::ast::{VarPattern, ParamPattern, Params};
 
 use crate::compile::{AccessKind, Name, StoreLoadKind};
 use crate::error::{CompileError, CompileErrors, CompileResult};
diff --git a/src/compiler/compile.rs b/src/erg_compiler/compile.rs
similarity index 93%
rename from src/compiler/compile.rs
rename to src/erg_compiler/compile.rs
index 30498d1e..ea5f34ea 100644
--- a/src/compiler/compile.rs
+++ b/src/erg_compiler/compile.rs
@@ -3,15 +3,15 @@
 //! コンパイラーを定義する
 use std::path::Path;
 
-use common::Str;
-use common::{log};
-use common::codeobj::{CodeObj, CodeObjFlags};
-use common::color::{GREEN, RESET};
-use common::config::{Input, ErgConfig, SEMVER, BUILD_INFO};
-use common::error::MultiErrorDisplay;
-use common::traits::{Runnable, Stream};
+use erg_common::Str;
+use erg_common::{log};
+use erg_common::codeobj::{CodeObj, CodeObjFlags};
+use erg_common::color::{GREEN, RESET};
+use erg_common::config::{Input, ErgConfig, SEMVER, BUILD_INFO};
+use erg_common::error::MultiErrorDisplay;
+use erg_common::traits::{Runnable, Stream};
 
-use parser::ParserRunner;
+use erg_parser::ParserRunner;
 
 use crate::codegen::CodeGenerator;
 use crate::effectcheck::SideEffectChecker;
diff --git a/src/compiler/effectcheck.rs b/src/erg_compiler/effectcheck.rs
similarity index 98%
rename from src/compiler/effectcheck.rs
rename to src/erg_compiler/effectcheck.rs
index ed68dac7..bd68dca3 100644
--- a/src/compiler/effectcheck.rs
+++ b/src/erg_compiler/effectcheck.rs
@@ -2,10 +2,10 @@
 //! SideEffectCheckerを実装
 //! 関数や不変型に副作用がないかチェックする
 
-use common::Str;
-use common::color::{GREEN, RESET};
-use common::log;
-use common::traits::Stream;
+use erg_common::Str;
+use erg_common::color::{GREEN, RESET};
+use erg_common::log;
+use erg_common::traits::Stream;
 
 use crate::varinfo::Visibility;
 use Visibility::*;
diff --git a/src/compiler/parser/.gitignore b/src/erg_compiler/erg_parser/.gitignore
similarity index 100%
rename from src/compiler/parser/.gitignore
rename to src/erg_compiler/erg_parser/.gitignore
diff --git a/src/compiler/parser/Cargo.toml b/src/erg_compiler/erg_parser/Cargo.toml
similarity index 64%
rename from src/compiler/parser/Cargo.toml
rename to src/erg_compiler/erg_parser/Cargo.toml
index 6723e6c3..c116c7a2 100644
--- a/src/compiler/parser/Cargo.toml
+++ b/src/erg_compiler/erg_parser/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "parser"
+name = "erg_parser"
 version = "0.1.0"
 description = "The Erg parser"
 authors = ["mtshiba <sbym1346@gmail.com>"]
@@ -7,11 +7,11 @@ license = "MIT OR Apache-2.0"
 edition = "2021"
 
 [features]
-debug = [ "common/debug" ]
-japanese = [ "common/japanese" ]
+debug = [ "erg_common/debug" ]
+japanese = [ "erg_common/japanese" ]
 
 [dependencies]
-common = { path = "../../common" }
+erg_common = { path = "../../erg_common" }
 
 [lib]
 path = "lib.rs"
diff --git a/src/compiler/parser/README.md b/src/erg_compiler/erg_parser/README.md
similarity index 100%
rename from src/compiler/parser/README.md
rename to src/erg_compiler/erg_parser/README.md
diff --git a/src/compiler/parser/ast.rs b/src/erg_compiler/erg_parser/ast.rs
similarity index 99%
rename from src/compiler/parser/ast.rs
rename to src/erg_compiler/erg_parser/ast.rs
index 052d28a2..535508b3 100644
--- a/src/compiler/parser/ast.rs
+++ b/src/erg_compiler/erg_parser/ast.rs
@@ -2,8 +2,8 @@
 use std::borrow::Borrow;
 use std::fmt;
 
-use common::{Str};
-use common::{
+use erg_common::{Str};
+use erg_common::{
     impl_display_for_single_struct,
     impl_locational, impl_locational_for_enum,
     impl_displayable_stream_for_wrapper,
@@ -11,11 +11,11 @@ use common::{
     fmt_vec, fmt_option, impl_display_for_enum,
     impl_display_from_nested, impl_nested_display_for_enum
 };
-use common::value::ValueObj;
-use common::error::Location;
-use common::set::Set;
-use common::traits::{Locational, Stream, NestedDisplay};
-use common::ty::SubrKind;
+use erg_common::value::ValueObj;
+use erg_common::error::Location;
+use erg_common::set::Set;
+use erg_common::traits::{Locational, Stream, NestedDisplay};
+use erg_common::ty::SubrKind;
 
 use crate::token::{Token, TokenKind};
 
diff --git a/src/compiler/parser/desugar.rs b/src/erg_compiler/erg_parser/desugar.rs
similarity index 98%
rename from src/compiler/parser/desugar.rs
rename to src/erg_compiler/erg_parser/desugar.rs
index e33d092e..8485aa97 100644
--- a/src/compiler/parser/desugar.rs
+++ b/src/erg_compiler/erg_parser/desugar.rs
@@ -5,10 +5,10 @@
 //! 型チェックなどによる検証は行わない
 #![allow(dead_code)]
 
-use common::{enum_unwrap, set};
-use common::{Str};
-use common::set::{Set};
-use common::traits::{Stream, Locational};
+use erg_common::{enum_unwrap, set};
+use erg_common::{Str};
+use erg_common::set::{Set};
+use erg_common::traits::{Stream, Locational};
 
 use crate::token::{Token, TokenKind};
 use crate::ast::{
diff --git a/src/compiler/parser/error.rs b/src/erg_compiler/erg_parser/error.rs
similarity index 93%
rename from src/compiler/parser/error.rs
rename to src/erg_compiler/erg_parser/error.rs
index 7b02d859..120a67f4 100644
--- a/src/compiler/parser/error.rs
+++ b/src/erg_compiler/erg_parser/error.rs
@@ -1,11 +1,11 @@
 //! defines `ParseError` and others.
 //!
 //! パーサーが出すエラーを定義
-use common::{impl_stream_for_wrapper, switch_lang};
-use common::Str;
-use common::config::Input;
-use common::error::{ErrorCore, ErrorDisplay, MultiErrorDisplay, Location, ErrorKind::*};
-use common::traits::Stream;
+use erg_common::{impl_stream_for_wrapper, switch_lang};
+use erg_common::Str;
+use erg_common::config::Input;
+use erg_common::error::{ErrorCore, ErrorDisplay, MultiErrorDisplay, Location, ErrorKind::*};
+use erg_common::traits::Stream;
 
 #[derive(Debug)]
 pub struct LexError(ErrorCore);
diff --git a/src/compiler/parser/lex.rs b/src/erg_compiler/erg_parser/lex.rs
similarity index 99%
rename from src/compiler/parser/lex.rs
rename to src/erg_compiler/erg_parser/lex.rs
index 13e2474d..60937711 100644
--- a/src/compiler/parser/lex.rs
+++ b/src/erg_compiler/erg_parser/lex.rs
@@ -1,10 +1,10 @@
 //! defines and implements `Lexer` (Tokenizer).
-use common::cache::Cache;
-use common::Str;
-use common::{fn_name_full, switch_lang, debug_power_assert, normalize_newline};
-use common::config::Input;
-use common::config::ErgConfig;
-use common::traits::{Locational, Runnable, Stream};
+use erg_common::cache::Cache;
+use erg_common::Str;
+use erg_common::{fn_name_full, switch_lang, debug_power_assert, normalize_newline};
+use erg_common::config::Input;
+use erg_common::config::ErgConfig;
+use erg_common::traits::{Locational, Runnable, Stream};
 
 use crate::error::{LexerRunnerError, LexerRunnerErrors, LexError, LexErrors, LexResult};
 use crate::token::{Token, TokenCategory, TokenKind, TokenStream};
diff --git a/src/compiler/parser/lib.rs b/src/erg_compiler/erg_parser/lib.rs
similarity index 91%
rename from src/compiler/parser/lib.rs
rename to src/erg_compiler/erg_parser/lib.rs
index d8eb584b..a666f748 100644
--- a/src/compiler/parser/lib.rs
+++ b/src/erg_compiler/erg_parser/lib.rs
@@ -1,6 +1,6 @@
 //! Implements `Parser` for Erg. `Parser` parses the source code to generate `AST`,
 //! and performs type checking and other optimizations if necessary.
-extern crate common;
+extern crate erg_common;
 
 pub mod desugar;
 pub mod error;
diff --git a/src/compiler/parser/main.rs b/src/erg_compiler/erg_parser/main.rs
similarity index 72%
rename from src/compiler/parser/main.rs
rename to src/erg_compiler/erg_parser/main.rs
index 91847380..0d479f35 100644
--- a/src/compiler/parser/main.rs
+++ b/src/erg_compiler/erg_parser/main.rs
@@ -3,11 +3,11 @@ extern crate parser;
 
 use std::process;
 
-use common::config::ErgConfig;
-use common::traits::Runnable;
+use erg_common::config::ErgConfig;
+use erg_common::traits::Runnable;
 
-use parser::lex::LexerRunner;
-use parser::ParserRunner;
+use erg_parser::lex::LexerRunner;
+use erg_parser::ParserRunner;
 
 fn main() {
     let cfg = ErgConfig::parse();
diff --git a/src/compiler/parser/parse.rs b/src/erg_compiler/erg_parser/parse.rs
similarity index 99%
rename from src/compiler/parser/parse.rs
rename to src/erg_compiler/erg_parser/parse.rs
index 5904ba5d..95a34bc2 100644
--- a/src/compiler/parser/parse.rs
+++ b/src/erg_compiler/erg_parser/parse.rs
@@ -5,15 +5,15 @@
 use std::fmt::Debug;
 use std::mem;
 
-use common::Str;
-use common::{debug_power_assert, enum_unwrap, fn_name, caused_by, switch_lang, switch_unreachable, log, set};
-use common::color::{GREEN, RED, RESET};
-use common::config::{Input, SEMVER, BUILD_INFO};
-use common::config::ErgConfig;
-use common::error::{Location};
-use common::set::Set;
-use common::traits::Runnable;
-use common::traits::{Locational, Stream};
+use erg_common::Str;
+use erg_common::{debug_power_assert, enum_unwrap, fn_name, caused_by, switch_lang, switch_unreachable, log, set};
+use erg_common::color::{GREEN, RED, RESET};
+use erg_common::config::{Input, SEMVER, BUILD_INFO};
+use erg_common::config::ErgConfig;
+use erg_common::error::{Location};
+use erg_common::set::Set;
+use erg_common::traits::Runnable;
+use erg_common::traits::{Locational, Stream};
 
 use crate::error::{ParseError, ParseErrors, ParseResult, ParserRunnerError, ParserRunnerErrors};
 use crate::ast::*;
diff --git a/src/compiler/parser/tests/ast_example.txt b/src/erg_compiler/erg_parser/tests/ast_example.txt
similarity index 100%
rename from src/compiler/parser/tests/ast_example.txt
rename to src/erg_compiler/erg_parser/tests/ast_example.txt
diff --git a/src/compiler/parser/tests/dependent.er b/src/erg_compiler/erg_parser/tests/dependent.er
similarity index 100%
rename from src/compiler/parser/tests/dependent.er
rename to src/erg_compiler/erg_parser/tests/dependent.er
diff --git a/src/compiler/parser/tests/fib.er b/src/erg_compiler/erg_parser/tests/fib.er
similarity index 100%
rename from src/compiler/parser/tests/fib.er
rename to src/erg_compiler/erg_parser/tests/fib.er
diff --git a/src/compiler/parser/tests/hello_world.er b/src/erg_compiler/erg_parser/tests/hello_world.er
similarity index 100%
rename from src/compiler/parser/tests/hello_world.er
rename to src/erg_compiler/erg_parser/tests/hello_world.er
diff --git a/src/compiler/parser/tests/stack.er b/src/erg_compiler/erg_parser/tests/stack.er
similarity index 100%
rename from src/compiler/parser/tests/stack.er
rename to src/erg_compiler/erg_parser/tests/stack.er
diff --git a/src/compiler/parser/tests/test.rs b/src/erg_compiler/erg_parser/tests/test.rs
similarity index 93%
rename from src/compiler/parser/tests/test.rs
rename to src/erg_compiler/erg_parser/tests/test.rs
index bd841a9e..9ea743c3 100644
--- a/src/compiler/parser/tests/test.rs
+++ b/src/erg_compiler/erg_parser/tests/test.rs
@@ -4,16 +4,16 @@ extern crate parser;
 mod tests {
     use std::iter::Iterator;
 
-    use common::config::{ErgConfig, Input};
-    use common::error::MultiErrorFmt;
-    use common::traits::Runnable;
+    use erg_common::config::{ErgConfig, Input};
+    use erg_common::error::MultiErrorFmt;
+    use erg_common::traits::Runnable;
 
-    // use compiler::parser;
+    // use erg_compiler::parser;
 
-    use parser::error::*;
-    use parser::lex::Lexer;
-    use parser::token::*;
-    use parser::ParserRunner;
+    use erg_parser::error::*;
+    use erg_parser::lex::Lexer;
+    use erg_parser::token::*;
+    use erg_parser::ParserRunner;
     use TokenKind::*;
 
     const FILE1: &str = "src/compiler/parser/tests/test1_basic_syntax.er";
diff --git a/src/compiler/parser/tests/test1_basic_syntax.er b/src/erg_compiler/erg_parser/tests/test1_basic_syntax.er
similarity index 100%
rename from src/compiler/parser/tests/test1_basic_syntax.er
rename to src/erg_compiler/erg_parser/tests/test1_basic_syntax.er
diff --git a/src/compiler/parser/tests/test2_advanced_syntax.er b/src/erg_compiler/erg_parser/tests/test2_advanced_syntax.er
similarity index 100%
rename from src/compiler/parser/tests/test2_advanced_syntax.er
rename to src/erg_compiler/erg_parser/tests/test2_advanced_syntax.er
diff --git a/src/compiler/parser/token.rs b/src/erg_compiler/erg_parser/token.rs
similarity index 97%
rename from src/compiler/parser/token.rs
rename to src/erg_compiler/erg_parser/token.rs
index 9027737a..0c88139d 100644
--- a/src/compiler/parser/token.rs
+++ b/src/erg_compiler/erg_parser/token.rs
@@ -4,12 +4,12 @@
 use std::fmt;
 use std::hash::{Hash, Hasher};
 
-use common::str::Str;
-use common::error::Location;
-use common::impl_displayable_stream_for_wrapper;
-use common::traits::{Stream, Locational};
-use common::value::ValueObj;
-use common::ty::Type;
+use erg_common::str::Str;
+use erg_common::error::Location;
+use erg_common::impl_displayable_stream_for_wrapper;
+use erg_common::traits::{Stream, Locational};
+use erg_common::value::ValueObj;
+use erg_common::ty::Type;
 
 /// 意味論的名前と記号自体の名前が混在しているが、Pythonの名残である
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
diff --git a/src/compiler/error.rs b/src/erg_compiler/error.rs
similarity index 97%
rename from src/compiler/error.rs
rename to src/erg_compiler/error.rs
index 107e7b70..9af75813 100644
--- a/src/compiler/error.rs
+++ b/src/erg_compiler/error.rs
@@ -1,15 +1,15 @@
 use std::fmt::Display;
 use std::ops::Add;
 
-use common::color::{GREEN, RED, YELLOW, RESET};
-use common::config::Input;
-use common::error::{ErrorCore, ErrorKind::*, ErrorDisplay, MultiErrorDisplay, Location};
-use common::traits::{Stream, Locational};
-use common::ty::{Type, Predicate};
-use common::{Str, fmt_iter};
-use common::{impl_stream_for_wrapper, switch_lang};
+use erg_common::color::{GREEN, RED, YELLOW, RESET};
+use erg_common::config::Input;
+use erg_common::error::{ErrorCore, ErrorKind::*, ErrorDisplay, MultiErrorDisplay, Location};
+use erg_common::traits::{Stream, Locational};
+use erg_common::ty::{Type, Predicate};
+use erg_common::{Str, fmt_iter};
+use erg_common::{impl_stream_for_wrapper, switch_lang};
 
-use parser::error::{ParserRunnerError, ParserRunnerErrors};
+use erg_parser::error::{ParserRunnerError, ParserRunnerErrors};
 
 use crate::hir::Expr;
 
diff --git a/src/compiler/eval.rs b/src/erg_compiler/eval.rs
similarity index 98%
rename from src/compiler/eval.rs
rename to src/erg_compiler/eval.rs
index 31eeb302..a6322d71 100644
--- a/src/compiler/eval.rs
+++ b/src/erg_compiler/eval.rs
@@ -1,17 +1,17 @@
 use std::mem;
 
-use common::Str;
-use common::{fn_name, set};
-use common::value::ValueObj;
-use common::dict::Dict;
-use common::rccell::RcCell;
-use common::set::{Set};
-use common::traits::Stream;
-use common::ty::{OpKind, TyParam, Type, Predicate, TyBound, ConstObj, SubrKind};
+use erg_common::Str;
+use erg_common::{fn_name, set};
+use erg_common::value::ValueObj;
+use erg_common::dict::Dict;
+use erg_common::rccell::RcCell;
+use erg_common::set::{Set};
+use erg_common::traits::Stream;
+use erg_common::ty::{OpKind, TyParam, Type, Predicate, TyBound, ConstObj, SubrKind};
 use OpKind::*;
 
-use parser::ast::*;
-use parser::token::Token;
+use erg_parser::ast::*;
+use erg_parser::token::Token;
 
 use crate::table::{SymbolTable, TyVarTable};
 use crate::error::{EvalError, EvalResult, TyCheckResult};
diff --git a/src/compiler/hir.rs b/src/erg_compiler/hir.rs
similarity index 98%
rename from src/compiler/hir.rs
rename to src/erg_compiler/hir.rs
index 60023efa..5ad5ff97 100644
--- a/src/compiler/hir.rs
+++ b/src/erg_compiler/hir.rs
@@ -1,19 +1,19 @@
 /// defines High-level Intermediate Representation
 use std::fmt;
 
-use common::{Str};
-use common::value::ValueObj;
-use common::error::Location;
-use common::traits::{HasType, Locational, Stream, NestedDisplay};
-use common::ty::{Type, TyParam, Constraint};
-use common::{
+use erg_common::{Str};
+use erg_common::value::ValueObj;
+use erg_common::error::Location;
+use erg_common::traits::{HasType, Locational, Stream, NestedDisplay};
+use erg_common::ty::{Type, TyParam, Constraint};
+use erg_common::{
     impl_locational, impl_locational_for_enum,
     impl_stream_for_wrapper, impl_display_for_enum,
     impl_nested_display_for_enum, impl_display_from_nested,
 };
 
-use parser::token::{Token, TokenKind};
-use parser::ast::{VarName, VarPattern, Params, DefId, fmt_lines};
+use erg_parser::token::{Token, TokenKind};
+use erg_parser::ast::{VarName, VarPattern, Params, DefId, fmt_lines};
 
 #[derive(Debug, Clone)]
 pub struct Literal {
diff --git a/src/compiler/initialize.rs b/src/erg_compiler/initialize.rs
similarity index 99%
rename from src/compiler/initialize.rs
rename to src/erg_compiler/initialize.rs
index 45dfb9bc..2f1a7c4d 100644
--- a/src/compiler/initialize.rs
+++ b/src/erg_compiler/initialize.rs
@@ -1,14 +1,14 @@
 //! defines type information for builtin objects (in `SymbolTable`)
 //!
 //! 組み込みオブジェクトの型情報を(記号表に)定義
-use common::{Str};
-use common::{set, debug_power_assert};
-use common::ty::{Type, TyParam, ConstObj};
+use erg_common::{Str};
+use erg_common::{set, debug_power_assert};
+use erg_common::ty::{Type, TyParam, ConstObj};
 use Type::*;
-use common::ty::type_constrs::*;
+use erg_common::ty::type_constrs::*;
 use ParamSpec as PS;
 
-use parser::ast::{VarName};
+use erg_parser::ast::{VarName};
 
 use crate::varinfo::{Mutability, Visibility, VarInfo, VarKind};
 use crate::table::{SymbolTable, ParamSpec, DefaultInfo};
diff --git a/src/compiler/lib.rs b/src/erg_compiler/lib.rs
similarity index 83%
rename from src/compiler/lib.rs
rename to src/erg_compiler/lib.rs
index 84bd15a9..de974484 100644
--- a/src/compiler/lib.rs
+++ b/src/erg_compiler/lib.rs
@@ -1,6 +1,6 @@
 //! defines the compiler for Erg (ergc).
-extern crate common;
-pub extern crate parser;
+extern crate erg_common;
+pub extern crate erg_parser;
 
 mod compile;
 pub use compile::*;
diff --git a/src/compiler/lower.rs b/src/erg_compiler/lower.rs
similarity index 98%
rename from src/compiler/lower.rs
rename to src/erg_compiler/lower.rs
index 0f1d5952..1a025bad 100644
--- a/src/compiler/lower.rs
+++ b/src/erg_compiler/lower.rs
@@ -1,15 +1,15 @@
 //! implements `ASTLowerer`.
 //!
 //! ASTLowerer(ASTからHIRへの変換器)を実装
-use common::{switch_lang, log, fn_name};
-use common::color::{GREEN, RED, RESET};
-use common::error::Location;
-use common::traits::{Locational, Stream, HasType};
-use common::ty::{Type, ParamTy};
-use common::get_hash;
+use erg_common::{switch_lang, log, fn_name};
+use erg_common::color::{GREEN, RED, RESET};
+use erg_common::error::Location;
+use erg_common::traits::{Locational, Stream, HasType};
+use erg_common::ty::{Type, ParamTy};
+use erg_common::get_hash;
 
-use parser::ast;
-use parser::ast::{AST};
+use erg_parser::ast;
+use erg_parser::ast::{AST};
 
 use crate::hir;
 use crate::hir::{HIR};
diff --git a/src/compiler/main.rs b/src/erg_compiler/main.rs
similarity index 58%
rename from src/compiler/main.rs
rename to src/erg_compiler/main.rs
index 3340f8ef..a71614df 100644
--- a/src/compiler/main.rs
+++ b/src/erg_compiler/main.rs
@@ -1,17 +1,17 @@
-extern crate common;
-extern crate compiler;
-extern crate parser;
+extern crate erg_common;
+extern crate erg_compiler;
+extern crate erg_parser;
 
 use std::process;
 
-use common::deserialize::Deserializer;
-use common::config::{ErgConfig};
-use common::traits::Runnable;
+use erg_common::deserialize::Deserializer;
+use erg_common::config::{ErgConfig};
+use erg_common::traits::Runnable;
 
-use compiler::Compiler;
+use erg_compiler::Compiler;
 
-use parser::lex::LexerRunner;
-use parser::ParserRunner;
+use erg_parser::lex::LexerRunner;
+use erg_parser::ParserRunner;
 
 fn main() {
     let cfg = ErgConfig::parse();
diff --git a/src/compiler/optimize.rs b/src/erg_compiler/optimize.rs
similarity index 100%
rename from src/compiler/optimize.rs
rename to src/erg_compiler/optimize.rs
diff --git a/src/compiler/ownercheck.rs b/src/erg_compiler/ownercheck.rs
similarity index 95%
rename from src/compiler/ownercheck.rs
rename to src/erg_compiler/ownercheck.rs
index 33244d36..d4a7b0ed 100644
--- a/src/compiler/ownercheck.rs
+++ b/src/erg_compiler/ownercheck.rs
@@ -1,11 +1,11 @@
-use common::Str;
-use common::{debug_power_assert, log};
-use common::color::{GREEN, RESET};
-use common::dict::Dict;
-use common::error::Location;
-use common::set::Set;
-use common::traits::{Stream, Locational, HasType};
-use common::ty::{Type, ArgsOwnership, Ownership};
+use erg_common::Str;
+use erg_common::{debug_power_assert, log};
+use erg_common::color::{GREEN, RESET};
+use erg_common::dict::Dict;
+use erg_common::error::Location;
+use erg_common::set::Set;
+use erg_common::traits::{Stream, Locational, HasType};
+use erg_common::ty::{Type, ArgsOwnership, Ownership};
 
 use crate::error::{OwnershipError, OwnershipErrors, OwnershipResult};
 use crate::hir::{HIR, Def, Signature, Accessor, Block, Expr};
diff --git a/src/compiler/table.rs b/src/erg_compiler/table.rs
similarity index 99%
rename from src/compiler/table.rs
rename to src/erg_compiler/table.rs
index ab81a2ea..bd126b5c 100644
--- a/src/compiler/table.rs
+++ b/src/erg_compiler/table.rs
@@ -6,18 +6,18 @@ use std::mem;
 use std::option::Option; // conflicting to Type::Option
 use std::cmp::Ordering;
 
-use common::Str;
-use common::ty::Constraint;
-use common::ty::RefinementType;
-use common::ty::fresh_varname;
-use common::{fn_name, get_hash, log, assume_unreachable, set, try_map, fmt_slice};
-use common::dict::Dict;
-use common::set::Set;
-use common::error::{Location, ErrorCore};
-use common::value::ValueObj;
-use common::levenshtein::levenshtein;
-use common::traits::{HasType, Locational, Stream};
-use common::ty::{
+use erg_common::Str;
+use erg_common::ty::Constraint;
+use erg_common::ty::RefinementType;
+use erg_common::ty::fresh_varname;
+use erg_common::{fn_name, get_hash, log, assume_unreachable, set, try_map, fmt_slice};
+use erg_common::dict::Dict;
+use erg_common::set::Set;
+use erg_common::error::{Location, ErrorCore};
+use erg_common::value::ValueObj;
+use erg_common::levenshtein::levenshtein;
+use erg_common::traits::{HasType, Locational, Stream};
+use erg_common::ty::{
     Type, TyParam, TyParamOrdering, TyBound, ConstObj,
     IntervalOp, FreeKind, HasLevel, SubrKind, SubrType, ParamTy, Predicate,
 };
@@ -26,9 +26,9 @@ use Type::*;
 use Predicate as Pred;
 use ValueObj::{Inf, NegInf};
 
-use parser::ast;
+use erg_parser::ast;
 use ast::{VarName, DefId, TypeSpec, ParamTySpec, PreDeclTypeSpec, SimpleTypeSpec, TypeBoundSpec, TypeBoundSpecs, ParamSig};
-use parser::token::{Token, TokenKind};
+use erg_parser::token::{Token, TokenKind};
 
 use crate::hir;
 use crate::eval::{Evaluator};
@@ -1725,7 +1725,7 @@ impl SymbolTable {
         // Never or T => T
         let mut union_pat_t = Type::Never;
         for (i, a) in pos_args.iter().skip(1).enumerate() {
-            let lambda = common::enum_unwrap!(&a.expr, hir::Expr::Lambda);
+            let lambda = erg_common::enum_unwrap!(&a.expr, hir::Expr::Lambda);
             if !lambda.params.defaults.is_empty() { todo!() }
             if lambda.params.len() != 1 {
                 return Err(TyCheckError::argument_error(
@@ -1819,7 +1819,7 @@ impl SymbolTable {
     }
 
     pub(crate) fn get_binop_t(&self, op: &Token, args: &[hir::PosArg], namespace: &Str) -> TyCheckResult<Type> {
-        common::debug_power_assert!(args.len() == 2);
+        erg_common::debug_power_assert!(args.len() == 2);
         let symbol = Token::symbol(binop_to_dname(op.inspect()));
         let mut op = hir::Expr::Accessor(hir::Accessor::local(symbol, Type::ASTOmitted));
         self.get_call_t(&mut op, args, &[], namespace).map_err(|e| {
@@ -1830,7 +1830,7 @@ impl SymbolTable {
     }
 
     pub(crate) fn get_unaryop_t(&self, op: &Token, args: &[hir::PosArg], namespace: &Str) -> TyCheckResult<Type> {
-        common::debug_power_assert!(args.len() == 1);
+        erg_common::debug_power_assert!(args.len() == 1);
         let symbol = Token::symbol(unaryop_to_dname(op.inspect()));
         let mut op = hir::Expr::Accessor(hir::Accessor::local(symbol, Type::ASTOmitted));
         self.get_call_t(&mut op, args, &[], namespace).map_err(|e| {
@@ -2191,7 +2191,7 @@ impl SymbolTable {
             (l, r @ (TyParam::Erased(_) | TyParam::MonoQVar(_) | TyParam::FreeVar(_))) =>
                 self.try_cmp(r, l, bounds).map(|ord| ord.reverse()),
             (_l, _r) => {
-                common::fmt_dbg!(_l, _r,);
+                erg_common::fmt_dbg!(_l, _r,);
                 None
             },
         }
diff --git a/src/compiler/tests/dependent.er b/src/erg_compiler/tests/dependent.er
similarity index 100%
rename from src/compiler/tests/dependent.er
rename to src/erg_compiler/tests/dependent.er
diff --git a/src/compiler/tests/fib.er b/src/erg_compiler/tests/fib.er
similarity index 100%
rename from src/compiler/tests/fib.er
rename to src/erg_compiler/tests/fib.er
diff --git a/src/compiler/tests/infer_arr.er b/src/erg_compiler/tests/infer_arr.er
similarity index 100%
rename from src/compiler/tests/infer_arr.er
rename to src/erg_compiler/tests/infer_arr.er
diff --git a/src/compiler/tests/side_effect.er b/src/erg_compiler/tests/side_effect.er
similarity index 100%
rename from src/compiler/tests/side_effect.er
rename to src/erg_compiler/tests/side_effect.er
diff --git a/src/compiler/varinfo.rs b/src/erg_compiler/varinfo.rs
similarity index 97%
rename from src/compiler/varinfo.rs
rename to src/erg_compiler/varinfo.rs
index bc1c7570..21560763 100644
--- a/src/compiler/varinfo.rs
+++ b/src/erg_compiler/varinfo.rs
@@ -1,10 +1,10 @@
 use std::fmt;
 
-use common::Str;
-use common::ty::{Type};
-use common::traits::HasType;
+use erg_common::Str;
+use erg_common::ty::{Type};
+use erg_common::traits::HasType;
 
-use parser::ast::DefId;
+use erg_parser::ast::DefId;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 #[repr(u8)]
diff --git a/src/lib.rs b/src/lib.rs
index 85d4f28e..6701c0d4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,3 @@
-extern crate common;
-extern crate compiler;
+extern crate erg_common;
+extern crate erg_compiler;
 pub mod dummy;
diff --git a/src/main.rs b/src/main.rs
index da93b65c..c382cf06 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,17 +1,17 @@
-extern crate compiler;
-extern crate parser;
+extern crate erg_compiler;
+extern crate erg_parser;
 extern crate erg;
 
 use std::process;
 
-use common::config::{ErgConfig};
-use common::deserialize::Deserializer;
-use common::traits::Runnable;
+use erg_common::config::{ErgConfig};
+use erg_common::deserialize::Deserializer;
+use erg_common::traits::Runnable;
 
-use parser::lex::LexerRunner;
-use parser::ParserRunner;
+use erg_parser::lex::LexerRunner;
+use erg_parser::ParserRunner;
 
-use compiler::Compiler;
+use erg_compiler::Compiler;
 
 use erg::dummy::DummyVM;
 
diff --git a/tests/test.rs b/tests/test.rs
index cd986cc4..554fb1ea 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -2,9 +2,9 @@ extern crate erg;
 
 mod tests {
     /*
-    use common::config::{ErgConfig, Input};
-    use common::error::MultiErrorFmt;
-    use common::traits::Runnable;
+    use erg_common::config::{ErgConfig, Input};
+    use erg_common::error::MultiErrorFmt;
+    use erg_common::traits::Runnable;
 
     const FILE3: &str = "tests/test3_object_system.er";
     */