Intel OpenMP vs LLVM OpenMP runtimes

Hello,

What are the differences between the Intel OpenMP runtime and the one use by LLVM?
According to https://www.openmprtl.org , the Intel C/C++ compilers and LLVM compilers use the same implementation (found here: https://openmp.llvm.org/).
Is it correct? Has it always been right in the past (such as for ICC 2014 and ICC 2016) ?

Thank You.