MBBS was a popular BBS system in the Nordic countries during the mid-1990s. It was created by a team of Oslo-based enthusiasts, led by Mike Robertson. As many BBS system of that era, it was only available for the DOS platform. Since one process could only handle one node, multitaskers such as DesqView or Windows were necessary in order to run multi-node BBSes. MBBS had to use the only viable means of interprocess communication under DOS, namely to read and write to a set of files in a common subdirectory. Since these files were access very often, many sysops moved them to a RAM disk.

MBBS's user interface was a command line where commands could be "stacked". This means that instead of typing a command, being asked to supply some parameters, etc., one could type them on one command line separated by a space or semicolon. An example is m sa g y, which expands to "marks, save message pointers, goodbye, yes". This user interface was copied in BBBS, to the degree that most valid MBBS command strings do the same in BBBS.

MBBS was released as uncrippled shareware by Gallagher & Robertson. It is now discontinued, and its final version, 10.4 was released in 1996.