http://www.hwaci.com/sw/tkhtml/ is the home page for one of the Tk HTML widgets that renders HTML into formatted text with hyperlinks. It is a compiled extension.
Kitten, a compilation of extensions for the TclKit user, includes compiled versions of tkhtml for Linux, Solaris, and Windows.
ActiveTcl 8.3.3.3 includes compiled versions of tkhtml 2.0 for Unix only [L1 ]. "[T]he next version will have Windows," according to Jeffrey Hobbs in early October.
TkHTML is one of the numerous packages in the Tcl community which has its own pecular build requirements. Be certain to read carefully the COMPILE.txt instructions - and take their instructions literally ! You do NOT just do a compile; make ; make install on this package!