+string literals and other features (Bison 1.25, 1995).
+
+Akim Demaille rewrote the parser in Bison, and changed the back end to
+use M4 (1.50, 2002).
+
+Paul Hilfinger added GLR support (Bison 1.50, 2002).
+
+Joel E. Denny contributed canonical-LR support, and invented and added
+IELR and LAC (Lookahead Correction) support (Bison 2.5, 2011).
+
+Paolo Bonzini contributed Java support (Bison 2.4, 2008).
+
+Alex Rozenman added named reference support (Bison 2.5, 2011).
+
+Paul Eggert fixed a million portability issues, arbitrary limitations,
+and nasty bugs.