History: The MIT project that produced Macsyma ran from about 1967 to 1982 or so. It was sponsored at various times by ARPA, NASA, DOE, various industrial contributors. The people in charge of the project sold an "exclusive" license to commercialize it to Symbolics, Inc. The rights were eventually sold to Macsyma, Inc, where it seems to have stopped. You can read more about Macsyma, and its role in the creation of the Open Source Software Movement including Linux, Netscape, the GNU project, and others, here (une copie locale se trouve dans la sec. 2.2).
Maxima is a clone of Macsyma, written in Common Lisp, and developed and released under the GNU public license.
