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, 3.4.1-4, and 4.0 were released between November 1998 and
October 2004, culminating in the January 2006 introduction of 4.1
(and service release 3.4.6).
GMT now is used by 
10,000 users worldwide in a broad range of disciplines.