This is a supplement to Ali Harlow's archive of historical Hack and NetHack source code, and should be read in conjunction with that. Its purpose is to answer the question "when did release x.y.z of NetHack become available?", or the converse "what version of NetHack was current on such-and-such a date?". Links are to newsgroup postings with release details, where available.
A successor to Andries Brouwer's Hack was first mooted by Mike Stephenson on 1987-03-06; this successor was released a few months later, and dubbed NetHack from its mode of development. The dates in the table below are those of the first posting of the relevant version or patchlevel to the comp.sources.games(.bugs) newsgroups (and hence may be a few days later than the dates in patchlevel.h, owing to the delays inherent in that release mechanism). I have put the version numbers into consistent form for ease of reference, though contemporary usage will have varied (3.0pl6, 3.0j...).
NetHack ceased being posted to comp.sources.games from 3.2 onwards; FTP download of the game had been available for some time, and now became the primary release medium (later followed by the establishment of the www.nethack.org website). The dates below are of the posting of the release announcement to rec.games.roguelike.nethack, where applicable.
The next version is under development, and will be available, as always, "when it's ready".