I've been using "AskSam", "a free-form information manager". The resent
versions are Windows-based; its searches are fast, reliable and flexible.
It doesn't do some things that a corpus linguist would like, such as
generate word lists and produce stats, but these are easily handled by a
host of unix tools. You can enquire further via their discussion list at
"ASKSAM-L@VTVM1.CC.VT.EDU"
John Milton
Hong Kong University of Science & Technology