Some concordance and text indexing programs

AntConc (Windows, Mac og Linux, free) http://www.antlab.sci.waseda.ac.jp/software.html

Simple Concordance Program (Windows, Mac, free) http://www.textworld.com/scp

The IMS Open Corpus Workbench (CWB), Linux, Windows, free http://cwb.sourceforge.net/

WordSmith (Windows, 50 pounds): http://www.lexically.net/wordsmith/

Concordance (Windows, 55 pounds) http://www.concordancesoftware.co.uk

MonoConc (Windows, $85) http://www.athel.com/mono.html

PhraseContext (Windows, 35 Euro) http://www.hjkm.dk/

R (with some programming) Quantitative Corpus Linguistics with R: A Practical Introduction by Stefan Th. Gries

For social sciences

Atlas.Ti http://www.atlasti.com/de/

Nudist http://www.springerlink.com/content/uxj45917q3207417/
http://caabi.ba.ttu.edu/Paper/Vasuki/Vasuki%20-%20NUDIST%20notes%28HTML%29.htm

Google seach for concordance software

Google search