A pretty widespread [Linux] distribution. 

[Jeff Hobbs] warned in the [Tcl chatroom] on 2003-05-20: "for reference for anyone else here, RH9 sucks, and sucks especially for what they did to Tk on it.  Do not use the RH9 default Tcl/Tk install."

What exactly did they do to it? - davidw

Good alternatives are [Debian] and [Suse].