Apparently a rather new tool for comparison of old versions of a page; discovered in hyperlinks in the output from NewRecentChanges.
Example: http:histDiff.cgi?page=SandBoxs&old=5&new=6&ip=61.51.173.18&time=1102731939
Rather less usefully, http:histDiff.cgi?page=SandBoxs&ip=61.51.173.18
History diff hack:
Compare any "older page version number" to any "newer page version number" (version numbers refer to versions in http://c2.com/wiki/history).
http://c2.com/cgi/histDiff.cgi?page=[X]&old=[Y]&new=[Z]
X = name of page Y = older version number Z = newer version numberExample: http://c2.com/cgi/histDiff.cgi?page=NewRecentChanges&old=63&new=95
Q: HistDiff output seems to be eliding all numbers. Is this a bug?
A: Yes, this unlikely bug was fixed 2005/02/26.
See also: HiddenFeatures, NewRecentChanges