Kenji Kita's list of all kinds of software related to corpus linguistics and NLP (includes POS taggers, parsers, stemmers, language identification, and corpus tools).
MI/X:
the X for Mac program we're using in the lab.
Tgrep2 A new-improved version of tgrep by Douglas L. T. Rohde.
MulLingProc A prototype program for processing multi-lingual texts, initially written for processing the Sheffield University's METER corpus. By Scott Songlin Piao.