SourceForge http://www.sf.net/ - aka SF - is an ambitious attempt to provide open source projects with freely available source code , bug, and request management, mailing list support, software distribution, and more. The effort has over 20,000 projects at this time.
A number of As of mid August, 2001 the massive collaborative project support site at SourceForge [L1 ]/[L2 ] has (at least) 250 projects in (or using) Tcl and Tcl/Tk. Some stay in the top downloads, or high-activity category. This page is started because so many projects have been moving to SF. To make the most of your own explorations of SF, you'll likely want to use CVS; before you start, read "Introduction to SourceForge.net Project CVS Services" [L3 ]".
Browse these projects from their trove list at:
http://sourceforge.net/softwaremap/trove_list.php?form_cat=182
Free to OpenSource developers, and development collaborators, SourceForge provides:
But rather than advertising SourceForge here, go browse the projects, or start your own, and announce it below:
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etc.
There is also a small code snippets library there:
http://sourceforge.net/snippet/browse.php?by=lang&lang=11
Please note that not everyone is perfectly content with sourceforge:
http://www.advogato.org/article/376.html
http://www.advogato.org/article/357.html
You may not agree with them, but they mention some reasonable points.