Implemented PEP 405 (Python virtual environments).

Lib/venv/scripts/nt/Activate.ps1

@@ -0,0 +1,34 @@
+$env:VIRTUAL_ENV="__VENV_DIR__"
+
+# Revert to original values
+if (Test-Path function:_OLD_VIRTUAL_PROMPT) {
+    copy-item function:_OLD_VIRTUAL_PROMPT function:prompt
+    remove-item function:_OLD_VIRTUAL_PROMPT
+}
+
+if (Test-Path env:_OLD_VIRTUAL_PYTHONHOME) {
+    copy-item env:_OLD_VIRTUAL_PYTHONHOME env:PYTHONHOME
+    remove-item env:_OLD_VIRTUAL_PYTHONHOME
+}
+
+if (Test-Path env:_OLD_VIRTUAL_PATH) {
+    copy-item env:_OLD_VIRTUAL_PATH env:PATH
+    remove-item env:_OLD_VIRTUAL_PATH
+}
+
+# Set the prompt to include the env name
+copy-item function:prompt function:_OLD_VIRTUAL_PROMPT
+function prompt {
+    Write-Host -NoNewline -ForegroundColor Green [__VENV_NAME__]
+    _OLD_VIRTUAL_PROMPT
+}
+
+# Clear PYTHONHOME
+if (Test-Path env:PYTHONHOME) {
+    copy-item env:PYTHONHOME env:_OLD_VIRTUAL_PYTHONHOME
+    remove-item env:PYTHONHOME
+}
+
+# Add the venv to the PATH
+copy-item env:PATH env:_OLD_VIRTUAL_PATH
+$env:PATH = "$env:VIRTUAL_ENV\__VENV_BIN_NAME__;$env:PATH"

Lib/venv/scripts/nt/Deactivate.ps1

@@ -0,0 +1,19 @@
+# Revert to original values
+if (Test-Path function:_OLD_VIRTUAL_PROMPT) {
+    copy-item function:_OLD_VIRTUAL_PROMPT function:prompt
+    remove-item function:_OLD_VIRTUAL_PROMPT
+}
+
+if (Test-Path env:_OLD_VIRTUAL_PYTHONHOME) {
+    copy-item env:_OLD_VIRTUAL_PYTHONHOME env:PYTHONHOME
+    remove-item env:_OLD_VIRTUAL_PYTHONHOME
+}
+
+if (Test-Path env:_OLD_VIRTUAL_PATH) {
+    copy-item env:_OLD_VIRTUAL_PATH env:PATH
+    remove-item env:_OLD_VIRTUAL_PATH
+}
+
+if (Test-Path env:VIRTUAL_ENV) {
+    remove-item env:VIRTUAL_ENV
+}

Lib/venv/scripts/nt/activate.bat

@@ -0,0 +1,31 @@
+@echo off
+set VIRTUAL_ENV=__VENV_DIR__
+
+if not defined PROMPT (
+    set PROMPT=$P$G
+)
+
+if defined _OLD_VIRTUAL_PROMPT (
+    set PROMPT=%_OLD_VIRTUAL_PROMPT%
+)
+
+if defined _OLD_VIRTUAL_PYTHONHOME (
+     set PYTHONHOME=%_OLD_VIRTUAL_PYTHONHOME%
+)
+
+set _OLD_VIRTUAL_PROMPT=%PROMPT%
+set PROMPT=__VENV_NAME__%PROMPT%
+
+if defined PYTHONHOME (
+     set _OLD_VIRTUAL_PYTHONHOME=%PYTHONHOME%
+     set PYTHONHOME=
+)
+
+if defined _OLD_VIRTUAL_PATH set PATH=%_OLD_VIRTUAL_PATH%; goto SKIPPATH
+
+set _OLD_VIRTUAL_PATH=%PATH%
+
+:SKIPPATH
+set PATH=%VIRTUAL_ENV%\__VENV_BIN_NAME__;%PATH%
+
+:END

Lib/venv/scripts/nt/deactivate.bat

@@ -0,0 +1,17 @@
+@echo off
+
+if defined _OLD_VIRTUAL_PROMPT (
+    set PROMPT=%_OLD_VIRTUAL_PROMPT%
+)
+set _OLD_VIRTUAL_PROMPT=
+
+if defined _OLD_VIRTUAL_PYTHONHOME (
+     set PYTHONHOME=%_OLD_VIRTUAL_PYTHONHOME%
+     set _OLD_VIRTUAL_PYTHONHOME=
+)
+
+if defined _OLD_VIRTUAL_PATH set PATH=%_OLD_VIRTUAL_PATH%
+
+set _OLD_VIRTUAL_PATH=
+
+:END

Lib/venv/scripts/nt/pysetup3-script.py

@@ -0,0 +1,11 @@
+#!__VENV_PYTHON__
+if __name__ == '__main__':
+    rc = 1
+    try:
+        import sys, re, packaging.run
+        sys.argv[0] = re.sub('-script.pyw?$', '', sys.argv[0])
+        rc = packaging.run.main() # None interpreted as 0
+    except Exception:
+        # use syntax which works with either 2.x or 3.x
+        sys.stderr.write('%s\n' % sys.exc_info()[1])
+    sys.exit(rc)