On the behalf of Spyder's development team (http://code.google.com/p/spyderlib/people/list), I'm pleased to announce that Spyder v2.1.10 has been released and is available for Windows XP/Vista/7, GNU/Linux and MacOS X: http://code.google.com/p/spyderlib/
This is a pure maintenance release -- a lot of bugs were fixed since v2.1.9: http://code.google.com/p/spyderlib/wiki/ChangeLog
Spyder is a free, open-source (MIT license) interactive development environment for the Python language with advanced editing, interactive testing, debugging and introspection features. Originally designed to provide MATLAB-like features (integrated help, interactive console, variable explorer with GUI-based editors for dictionaries, NumPy arrays, ...), it is strongly oriented towards scientific computing and software development. Thanks to the `spyderlib` library, Spyder also provides powerful ready-to-use widgets: embedded Python console (example: http://packages.python.org/guiqwt/_images/sift3.png), NumPy array editor (example: http://packages.python.org/guiqwt/_images/sift2.png), dictionary editor, source code editor, etc.
Description of key features with tasty screenshots can be found at: http://code.google.com/p/spyderlib/wiki/Features
On Windows platforms, Spyder is also available as a stand-alone executable (don't forget to disable UAC on Vista/7). This all-in-one portable version is still experimental (for example, it does not embed sphinx -- meaning no rich text mode for the object inspector) but it should provide a working version of Spyder for Windows platforms without having to install anything else (except Python 2.x itself, of course).
Last, but not least, we welcome any contribution that helps making Spyder an efficient scientific development/computing environment. Join us to help creating your favourite environment! (http://code.google.com/p/spyderlib/wiki/NoteForContributors)