[http://wiki.wxpython.org/index.cgi/PythonCardEditor PythonCardEditor]

Unix/Windows/Mac

Extensible in Python, part of PythonCard.

[http://cooledit.sourceforge.net/ Cooledit]

Unix/X

Extensible in Python

[http://www.crisp.demon.co.uk/ CRiSP]

Unix/Windows

BRIEF-compatible

[http://www.lugaru.com/ Epsilon]

Windows, Linux, FreeBSD, and OS/2

Has Python mode module available upon request.

[http://fte.sourceforge.net/ FTE Text Editor]

Windows, Unix, DOS, OS/2 console, Unix/X

Supports lots of languages, including Python; doesn't seem programmable

[http://www.jasspa.com/ Jasspa's MicroEmacs]

Unix / Windows

Supports Python syntax and a Python-specific menu.

[http://space.mit.edu/~davis/jed/ JED]

Unix, VMS, MSDOS, OS/2, BeOS, QNX, and Windows.

[http://www.jedit.org/ jEdit]

Java

Includes plugin that allows editor scripting using Python (via Jython).

[http://www.jext.org/ Jext]

Java

A Java text editor which offers embedded Python scripting (thanks to Jython).

[http://sourceforge.net/projects/joe-editor/ JOE]

Unix.

GnuEmacs / XEmacs

Unix/Windows/Mac

Python support with PythonMode.

[http://www.kde.org/ KWrite]

Unix

Advanced editor for the KDE environment - supports Python syntax.

[http://www.moleskine.f2s.com/ Moleskine]

Linux/FreeBSD

Written in Python, so should be extensible using Python.

[http://nedit.org/ NEdit]

Unix/VMS/Win32/MacOS X

X-Based, Python support builtin.

[http://www.rexx.com/~dkuhlman/ pyeditor]

Unix (and Windows?)

Editor written in Python atop PyScintilla and PyGtk.

[http://quanta.sourceforge.net/ Quanta KDE]

(Unix/Linux only?)

Full-featured web development environment that also supports Python.

[http://www.scintilla.org/ SciTE]

Unix/Windows

Part of Scintilla

[http://www.vim.org/ VIM]

Unix/Windows/MacOS/ etc.

[http://www.slickedit.com/ Visual Slick Edit]

Windows, Linux, Several Unix Flavors, OS/390

Syntax coloring, popup function arguments, class hierarchy browser, other nice Python features.

[http://www.cs.yorku.ca/~oz/wily/ Wily]

Unix

Acme clone for Unix. Can connect to it (and control it) from Python.

[http://anjuta.sourceforge.net/ Anjuta]

Unix + GNOME

Cross-language IDE; syntax coloring & folding for Python.

[http://www.thekompany.com/products/blackadder/ BlackAdder]

Windows/Linux

Commercial with all the features of IDLE, support for Ruby, and Qt GUI editor.

[http://boa-constructor.sourceforge.net/ BOA Constructor]

Python + wxPython

RAD GUI building IDE, similar to Delphi.

[http://www.python.org/ IDLE]

Python + Tkinter

Part of Python distribution.

[http://idlefork.sourceforge.net/ IDLEfork]

Python + Tkinter

An experimental fork of IDLE.

[http://www.activestate.com/Products/Productivity/ASPN_Komodo/ Komodo]

Windows/Linux

Commercial cross-language IDE.

PythonWin

Windows

Available either as part of ActiveState's ActivePython distribution (which is not open source) or as part of the Win32all extensions from Mark's pages (which is open source).

PythonWorks Pro

Windows/Linux

SecretLabs' commercial IDE. Includes Tk layout editor.

[http://www.activestate.com/VisualPython/ Visual Python]

Windows 2000/XP with Visual Studio.NET

A Python plug-in for Visual Studio.NET

WingIde

Windows/Linux

Commercial IDE with networked debugger, source browser, and syntax coloring/auto-completing editor.

[http://www.roebling.de/ wxDesigner]

Unix/Windows/Mac

Cross-language GUI dialog designer with integrated support for editing your Python callback functions.