The GMT system was initiated in late 1987 at Lamont-Doherty
Earth Observatory, Columbia University by graduate students Paul
Wessel and Walter H. F. Smith. Version 1 was officially introduced
to Lamont scientists in July 1988. GMT 1 migrated by word of mouth
(and tape) to other institutions in the United States, UK, Japan, and
France and attracted a small following. Paul took a Post-doctoral
position at SOEST in December 1989 and continued the GMT development.
Version 2.0 was released with an article in EOS, October 1991, and
quickly spread worldwide. We obtained NSF-funding for GMT version 3.0 in 1993 which was released with another article in EOS
on August 15, 1995. Significantly improved versions (3.1-3.3,
3.3.1-6), 3.4 and 3.4.1-4 were released between November 1998 and
January 2004, culminating in the October 2004 introduction of 4.0
(and service release 3.4.5).
GMT now is used by 
6,000 users worldwide in a broad range of disciplines.