The libcomprex library transparently handles automatic compression and
decompression of files. The API is similar to C's built-in file access
functions, which provides a smooth transition to libcomprex.
libcomprex can also open uncompressed files, making it a good
replacement for the native file access functions.

libcomprex is part of the GNUpdate project.

libcomprex is currently in development (so should not be used in
stable products).