The fhist package contains 3 programs, the rcs-like fhist, diff-like fcomp and diff3-like fmerge. These are often used with aegis.
Created attachment 287 [details] ebuild for fhist-1.8 (New Package)
The aegis ebuild is bug#957. Not strictly a dependancy but there's very little use of fhist without aegis.
Ebuild freeze until 1.0 is out.
Available as dev-util/fhist-1.8