Recently I installed Mathematica 10.1 and noticed two different files (they have the same length, but different hashes) in the installation folder: MathKernel.exe and WolframKernel.exe. It appears that the latter one is actually running when I start a new kernel session. IIRC, previous versions of Mathematica had only MathKernel.exe.
What's the difference between these two files, and what's the purpose of having both of them?