PyScripter!

Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features.

A free, open-source Integrated Development Environment for software developers. You get all the tools you need to create professional desktop, enterprise, web, and mobile applications with the Java language, C/C++, and even dynamic languages such as PHP, JavaScript, Groovy, and Ruby. NetBeans IDE is easy to install and use straight out of the box and runs on many platforms including Windows, Linux, Mac OS X and Solaris.The download section conveniently offers prepackaged bundles/installers for each supported programming language containing only required plugins. »

Python IDE with refactoring, code completion, on-the-fly code analysis, graphical debugger, and coding productivity orientation. It can work with Git, Mercurial, CVS, Subversion, GitHub.

Aptana Studio is a complete web development environment that combines powerful authoring tools with a collection of online hosting and collaboration services that help you and your team do more. Includes support for PHP, CSS, FTP, and more...

Qt Creator is a cross-platform C++, JavaScript and QML integrated development environment which is part of the SDK for the Qt Framework.

IPython is an interactive shell for the Python programming language that offers enhanced introspection, additional shell syntax, syntax highlighting, tab completion and rich history. It is a component of the SciPy package.

SciTE is a SCIntilla based Text Editor. Originally built to demonstrate Scintilla, it has grown to be a generally useful editor with facilities for building and running programs. It is best used for jobs with simple configurations - I use it for building test and demonstration programs as well as SciTE and Scintilla, themselves.

Light Table is a new interactive IDE that lets you modify running programs and embed anything from websites to games. It provides the real time feedback we need to not only answer questions about our code, but to understand how our programs really work.

Spyder (previously known as Pydee) is a free open-source Python development environment providing MATLAB-like features in a simple and light-weighted software, available for Windows XP/Vista/7, GNU/Linux and Mac OS X.

Code smarter and faster with Komodo IDE, the cross-platform professional development environment for dynamic languages and open technologies. Komodo's award-winning feature set includes standard editor functionality like code formatting, commenting, auto-indent and syntax coloring, plus intelligent tools for debugging, regular expressions, team development and customization.

Default IDE which come installed with the Python programming language. It aims to be simple and intuitive, and is especially useful for programmers just learning Python. The editor has syntax highlighting, search features, class browsers, and runs Python scripts in a separate, protected process.