The Shared Procedure Archive (SPA) was originally developed at McGill University, starting in about 1999. The intention of the archive was to reduce create an easy-to-use diagnostics package for meteorological applications. It began as a set of portable FORTRAN77 functions and subroutines, and has since then grown into an evolving FORTRAN90 library with a Graphical User Interface (GUI, MetCal) and perl scripts which enable the developer's interface.
As noted in the licensing and copying agreement (see Copying Conditions) we encourage all users of this software to become developers and to contribute to the evolution of the SPA. Please share the library entries that you develop so that others may benefit from your efforts.