Yup, used in all the FPGA software tools. A lot of the new stuff coming out of Quartus at least is being written in Python though, or rewritten as such. Having worked in the field for the past year, I've definitely got quite a few gripes with the Tcl after some exposure.
The syntax is not intuitive, especially for a scripting language. The standard library is far too small, basically just a subset of the C standard library plus regexps. The only true data types in Tcl are strings and associative arrays. As such, Tcl scripts do not scale very well. The performance is generally abysmal, not just because of the magic string conversions, but because standard library functions are incredibly slow in cases that are hard to avoid. Tcl fully parses lines before deciding that they should be executed (in the case of a command) or ignored (in the case of a comment). You should think of a comment as a "do nothing" command, rather than as a comment as in other languages. While not too egregious, if you're used to other languages that quirk causes numerous grievances.
One positive is it's really easy to drop down into C or C++ when you come across tasks that make more sense in a lower-level language, so if you're using it for that purpose it's good.
The syntax is not intuitive, especially for a scripting language. The standard library is far too small, basically just a subset of the C standard library plus regexps. The only true data types in Tcl are strings and associative arrays. As such, Tcl scripts do not scale very well. The performance is generally abysmal, not just because of the magic string conversions, but because standard library functions are incredibly slow in cases that are hard to avoid. Tcl fully parses lines before deciding that they should be executed (in the case of a command) or ignored (in the case of a comment). You should think of a comment as a "do nothing" command, rather than as a comment as in other languages. While not too egregious, if you're used to other languages that quirk causes numerous grievances.
One positive is it's really easy to drop down into C or C++ when you come across tasks that make more sense in a lower-level language, so if you're using it for that purpose it's good.