Unlike other cross-platform GUI toolkits (Tcl/Tk, Qt, AWT) wxWidgets supports the native look-and-feel of the local OS. And unlike Qt, wxWidgets is truly Open Source. It also works with virtually every standard C++ compiler. It is a perfect solution for organizations interested in porting Windows applications to Linux and other platforms. And with Mac OS X and Linux gaining marketshare daily, many organizations -- including Xerox, Advanced Micro Devices, AOL, Lockheed Martin, NASA--have adopted wxWidgets in order to support Windows, Linux, OS X, and Unix for their applications.

See http://www.wxwidgets.org/

And wxWidgets is HOT. Mitch Kapor's OSAF is using wxWidgets for its Chandler PIM. Bram Cohen uses wxWidgets for BitTorrent. Borland has added enormous credibility to wxWidgets by incorporating it into its newest C++ IDE: C++ BuilderX. wxWidgets is Borland's cross-platform development solution.