So, in the name 'libcmt', 'libc' is the (more or less) traditional name for the C library. They provide both 'debug' and 'release' versions of three basic types of libraries: single-threaded (always statically linked), multi-threaded statically linked, and multi-threaded dynamically linked (though, depending on the compiler version you're using, some of those may not be present). Yes, libcmt is (one of several) implementations of the C standard library provided with Microsoft's compiler.
