tkml is a library written in pure Tcl which makes use of the Itcl object oriented package for providing its users (Tcl/Tk programmers) with a way of easily creating GUIs based on XML text with a pre-defined set of tags and corresponding attributes.
Instigate GUI Toolkit is an Abstraction for multiple GUI Toolkits allowing to write single GUI code which can run on multiple platforms and with multiple GUI back-ends. Now it supports QT and gtkmm back-ends on Linux. Work on GTK+ and EWL is ongoing.