Rar is proprietary, so you can’t freely implement it. Only the decompression code is freeware, and you have to implement it as is. The license includes clauses against reverse engineering and rewriting the code.
Microsoft could totally pay the fees, but you know how scummy they are.
I just looked on my work laptop and it has zip, 7z, bzip2, gzip, xz, zstandard so it definitely has a few built in, no rar though
Rar is proprietary, so you can’t freely implement it. Only the decompression code is freeware, and you have to implement it as is. The license includes clauses against reverse engineering and rewriting the code.
Microsoft could totally pay the fees, but you know how scummy they are.