GT.M

GT.M is an implementation of MUMPS from FIS, better known as Fidelity. It is widely used in the banking world, and in addition, it will run VA VistA. At present the only alternative is Cache

Fidelity is the maintainer of GT.M. In addition to their open source version, they provide nonfree software that runs on the Sun SPARC line of high performance servers. They also offer service contracts to open source users.

Extensive documentation from Fidelity is here. See also GT.M Programmer's Guide.

GT.M can support VistA. The portability layer of the Kernel is known to work with GT.M on VMS and also GT.M on the Linux Operating System.