Long, growing article, with links to related topics. [Wikipedia]

has info about the MUMPS (M) computer language. Features include an M Job Opportunities database, the M User Directory, and links about MUMPS.

Compiler and interpreter for Linux, Solaris, Windows. Implements much of most recent Mumps standard. [free]

Program development, consulting, training, support services; VC/m web-enabled configuration management system to manage documents and source code across many OSs, and add-in tools for Cache and related M technologies.

A non-profit educational organisation. Its aims are to further the utilisation, improvement and understanding of Cache and the M Technology language and its dissemination within the UK and Ireland.

Implementation of M-Technology+ for Linux. [Open Source]

The German MUG (in German, of course)

Makes M21, implementation of M language/database for the 21st Century.

Information about MSM-WS, an M implementation for Win32

A forum and web site for users of InterSystems tools and M in general