Major cross-platform (Windows, Mac OS X, Unix-like) GUI toolkits are available for Python:
- is a set of bindings for the GTK widget set. It provides an object oriented interface that is slightly higher level than the C one. It comes with many more widgets than Tkinter provides, and has good Python-specific reference documentation. There are also bindings to GNOME. An online tutorial is available.
- PyQt is a sip-wrapped binding to the Qt toolkit. Qt is an extensive C++ GUI application development framework that is available for Unix, Windows and Mac OS X. sip is a tool for generating bindings for C++ libraries as Python classes, and is specifically designed for Python. The PyQt3 bindings have a book, GUI Programming with Python: QT Edition by Boudewijn Rempt. The PyQt4 bindings also have a book, Rapid GUI Programming with Python and Qt, by Mark Summerfield.
- wxPython is a cross-platform GUI toolkit for Python that is built around the popular wxWidgets (formerly wxWindows) C++ toolkit. It provides a native look and feel for applications on Windows, Mac OS X, and Unix systems by using each platform’s native widgets where ever possible, (GTK+ on Unix-like systems). In addition to an extensive set of widgets, wxPython provides classes for online documentation and context sensitive help, printing, HTML viewing, low-level device context drawing, drag and drop, system clipboard access, an XML-based resource format and more, including an ever growing library of user-contributed modules. wxPython has a book, wxPython in Action, by Noel Rappin and Robin Dunn.
PyGTK, PyQt, and wxPython, all have a modern look and feel and more widgets than Tkinter. In addition, there are many other GUI toolkits for Python, both cross-platform, and platform-specific. See the GUI Programming page in the Python Wiki for a much more complete list, and also for links to documents where the different GUI toolkits are compared.