libotf -- http://www.m17n.org/libotf/
fontconfig -- http://freedesktop.org/Software/fontconfig
xft -- http://freedesktop.org/Software/Xft
- gd -- http://www.boutell.com/gd/http/gd-1.8.4.tar.gz
+ gd -- http://www.boutell.com/gd/
In addition, for finding a word boundary in Thai text, "configure"
checks the existence of these libraries (libthai is preferred):