Is RAR archive format planned ? I know it's proprietary, but decompression is open source. Sometimes that's what you're given to decompress.
Also, does this library offer the possibility of random seek inside an archive's files - select arbitrary byte ranges of a particular file (without full decompression, if the format allows it) ?
It is not very clear from the Readme what the use scope of this library is, but i'd guess it only works with raw streams ?