"One that has survived is Lattice C, one of the most performant of the compilers tested by Byte. Lattice C was so good that it was licensed by Microsoft and sold as Microsoft C V1.0 before being replaced by Microsoft’s own in-house Microsoft C V2.0 compiler."
I read that, but I'm not convinced it is correct. It is a best ambiguous--development could have gone internal but started with the Lattice codebase. It is also incorrect at least as to version numbers. MSC 3.0 was the first version that wasn't developed by Lattice, whatever the provenance of the source
"The Microsoft C compiler has interesting historical roots. Although Microsoft itself works with C, this compiler is not a direct Microsoft product. Instead, it is an adaptation of the famous and highly regarded Lattice C compiler."
Another historical note, if I remember correctly, Microsoft was the last C compiler vendor on MS-DOS to add C++ support, which happened on Microsoft C/C++ v7.0 release, their last release for MS-DOS as well, before Visual C++ came to be.
"One that has survived is Lattice C, one of the most performant of the compilers tested by Byte. Lattice C was so good that it was licensed by Microsoft and sold as Microsoft C V1.0 before being replaced by Microsoft’s own in-house Microsoft C V2.0 compiler."