Scheme was earlier developed than Common Lisp. But that's not the whole picture. The mainline of Lisp, which Common Lisp and the early Scheme (partly) is based

Scheme was earlier developed than Common Lisp. But that's not the whole picture. The mainline of Lisp, which Common Lisp and the early Scheme (partly) is based on, existed earlier: Lisp 1.5 and then Maclisp. Scheme was then developed over several decades. It took 13 years to get Common Lisp from an idea to the ANSI Common Lisp standard. Sometimes the same people were involved. 1973 Maclisp 1974 Lisp Machine Lisp 1975 Scheme 1981 CL development started 1984 Common Lisp the Language published 1985 Scheme R2RS 1986 Scheme R3RS 1989 Common Lisp the Language II published (with CLOS, error handling, ...) 1990 IEEE Standard for Scheme published 1991 Scheme R4RS 1994 ANSI CL Standard published 1998 Scheme R5RS 2007 Scheme R6RS 2013 Scheme R7RS small