[Someone want to insert some URLs here for what Linux is, where a variety of distributions can be found, etc.? ]
One popular distribution of Linux is Suse - where one of the Tcl community works to maintain a great Tcl presence in the distribution.
Csan I am using Debian GNU/Linux,[L1 ] which my "favorite Linux distribution, first and foremost for its technical qualities, and the fact that it is Free Software." - I am quoting davidw