I’m not sure if I can definitively take credit for the name, but in 1997 or so, while working at Netscape, I wrote a closed-source perl script called “cvsblame” that displayed an annotated listing of a file with each line prefixed by the author/revision/date of its most recent change. Later on, “cvs blame”, a.k.a. “cvs annotate”, commands were added to the CVS revision control system, though it appears the implementation was independent of mine. As others have noted, other versions control systems, including subversion and git have added similar functionality.