The Microsoft Build Engine is a platform for building applications.
=== NOTE: ===
OBS process packages without internet connection. It's almost impossible to automate build of such complex package that relies on stuff downloaded from internet. Also, downloaded binary components needed for msbuild compilation are not compatible with modern SUSE distros.
So, this packages is just a repackage of centos 7 packages from official repo https://download.mono-project.com/repo/centos7-stable/m/msbuild