What Does M Mean?
M is a domain-specific, textual and declarative programming language, which is used for building application models prior to the actual coding execution. M is used primarily for building domain and software models with the use of Extensible Application Markup Language (XAML) features.
Techopedia Explains M
M is a domain-specific language targeting specific, rather than general, types of issues. The domain addressed by M, which was intended to define software and applications models via textual language, targeted end-users with little or no programming experience. Thus, end users were able to subjectively define how data would be handled throughout the software solution, which eliminated dependence on the underlying technology of an application.