A GUI Toolkit provides facilities for creating and maintaining GUI's. Tk, which was created expressly for Tcl by John Ousterhout, is the predominant GUI toolkit for Tcl.
- going strong for over two decades, and still considered by many to be the most productive tool for GUI development
- Fox Toolkit
- cross-platform, licensed under the LGPL, written in C++, focused on using a low-level interface on supported platforms, no Tcl bindings yet
- cross-platform, dual-licensed, written in C++
- cross-platform, license similar to but more permissive than LGPL, written in C++
- Alternative GUI toolkits
- could probably be folded into this page