A quick scan of sourceforge gives a bunch of projects whose name begins with tcl. I'm going to trawl through them all. Around a hundred. Who knows what we'll find.
Project front pages
Projects with no front page
In these cases, check for http://sf.ne/projects/ followed by the project name that is before the .sourceforge.net name in the following list. I think you will find whether the project is Tcl related or not.
Projects that are Tcl based without a Tcl prefix
Here are some sourceforge projects for someone to check out to see if they are our tcl
https://www.tcl-lang.org/community/tcl2004/Papers/RonFox/fox.pdf for a paper on this presented at Tcl 2004.
Are you using sf.net's search engine to search for tcl? I don't know if there are also projects which use tcl but which don't have tcl in the search description.