p9troff is a port of Plan9 troff tools to Linux. It contains
troff, tr2ps (dpost), eqn, tbl, and pic.
xhtml2man is an XSLT script that converts properly formatted, semantically meaningful XHTML pages into man pages. The script's primary purpose is to make it easy to output man pages for things that have previously been documented in XHTML.
An open source Java library for DDMS.
A readline wrapper.