What: wordnet
Where: http://www.cogsci.princeton.edu/%7Ewn/
Description: Online lexical reference system.
A lexical database for the English language
Updated: 07/1999
Contact: mailto:[email protected]
That is, a dictionary.
There is an online version [L1 ] and an off-line version [L2 ]. The off-line version is avalable for Windows and Unix.
It is mentioned here because it is based on Tcl/Tk. Don't expect too much. It works, but is rather poorly designed.