I know Tcl already since version 7.3. But I haven't used it very often in the past (only one small in-house tool at my employers site). But now I am using it successfully for a larger very important component within a big project mainly written in C++.
Although I have to confess, that Tcl was not my first choice (I would had taken another language, if the other possible one wouldn't have been Perl -- that I really do not like to write C++ extensions for), but now I am really happy with my decision to use Tcl instead writing the whole component in C++.
The more I know Tcl, the more I like its simplicity and power.
Although ... sometimes I really damn the type shimmering, that often makes my design of own written extensions more complicate than necessary - I guess, I cannot get all, can I?