Schoonschip was one of the first computer algebra systems, developed in 1963 by Martinus J. G. Veltman, for use in particle physics.
"Schoonschip" refers to the Dutch expression "schoon schip maken": to make a clean sweep, to clean/clear things up (literally: to make the ship clean).
Veltman initially developed the program to compute the quadrupole moment of the W boson, the computation of which involved "a monstrous expression involving in the order of 50,000 terms in intermediate stages" [2] The initial version, dating to December 1963, ran on an IBM 7094 mainframe.
[3] In 1983 it was ported to the Motorola 68000 microprocessor, allowing its use on a number of 68000-based systems running variants of Unix.
Contacts with Veltman about Schoonschip have been important for Stephen Wolfram in building Mathematica.