Columbia MM (Mail Manager) is a computer program for reading email using a command-line interface. It was developed at Columbia University between 1984 and 1990, and is a Unix reimplementation of a 1978 TOPS-20 email program, also known as MM, which in turn was an update of an earlier program by Michael McMahon of SRI International. Columbia MM has also been built on other platforms, including DOS and VMS. After a lull in development in 1990, MM development picked up again in 2002 with an interim release, including changes for Linux portability and POP support.