If you ever need to unzip data compressed with zlib without a header (e.g. produced by Erlang’s zlib:zip), it pays to be aware that

windowBits can also be -8..-15 for raw inflate. In this case, -windowBits determines the window size. inflate() will then process raw deflate data, not looking for a zlib or gzip header, not generating a check value, and not looking for any check values for comparison at the end of the stream. (zlib.h)