The GSL project was initiated in 1996 by physicists Mark Galassi and James Theiler of Los Alamos National Laboratory.

The "overall development of the library and the design and implementation of the major modules" was carried out by Brian Gough and Gerard Jungman.

In the following years, the library expanded only slowly; as the documentation stated, the maintainers were more interested in stability than in additional functionality.

Vigorous development resumed with publication of version 2.0 in October 2015, which included user contributed patches.

Finally, there is (limited, as of April 2020) support for allowing the user to create classes to represent a parameterised function as a functor.