The Xft library combines fontconfig [http://www.fontconfig.org], FreeType [http://www.freetype.org], and the X Render extension to provide anti-aliased fonts under X11.  Xft 2.0 is included in most recent Linux distributions (circa May 2003).  Mozilla, Qt, and GTk have all been updated to use Xft.

Experimental support for Xft in Tk 8.5 is available as patch #535541 from SourceForge [http://sourceforge.net/tracker/?func=detail&aid=535541&group_id=12997&atid=312997].
There are still (31 May 2003) a few quirks and bugs to be worked out, but overall it works pretty well.
After applying the patch, re-run autoconf, then run:

    sh ./configure --enable-xft
    make clean
    make