Source code documentation generator tool.
Doxygen is a documentation system for C++, C, Java, Objective-C, Python, IDL (Corba and Microsoft flavors), Tcl and to some extent PHP, C#, and D.
http://www.stack.nl/~dimitri/doxygen/
As of version 1.7.5. doxygen does support Tcl directly (see doxygen+tcl).
It is also possible to write a filter that convert the Tcl source code in to something similar to C++. Doxygen can call this filter when it is needed.
George Petasis: There is a small flex tool than act as a doxygen filter, to generate documentation with doxygen from tcl files. It can be found at [L1 ]
A little doxygen converter is another one. (pmarin: Actually It implements a subset of doxygen.)