Offzip is probably very known now, anyway it's a decompressor and scanner of zlib and deflate data... the classical algorithm used in the ZIP files and in the majority of games.
I have just improved the tool in the current 0.3.6 version, the following is the changelog:
added the -c option that allows to guess and dump the chunked files, option -D to specify dictionary, -d to visualize the hexdump of the data before and after the compressed streams, statistics information, offset where the compressed streams ends, amount of bytes between the current compressed stream and the previous one, zlib header and crc information, updated extensions guesser (strnicmp fix for Linux)
From the point of view of who makes the scripts there are the ending offset and the amount of space between the streams that are very useful.
One of the most interesting features is just the -c option to guess the chunked files, so those files that are splitted in many compressed and non-compressed pieces.
Imagine to have a file splitted in the following way:
Offset Compressed Uncompressed
0x00000000: 0x00001000 -> 0x00004000
0x00001000: 0x00001000 -> 0x00004000
0x00002000: #no compressed data here
0x00003000: 0x00001000 -> 0x00004000
0x00004000: 0x00000080 -> 0x00000100
In this situation will be enough to use "offzip -a -c 0x4000" for being able to dump the original file.
Basically the tool thinks that the last chunk is the one smaller than the uncompressed chunk size (0x4000 in the example) and it will dump the non-compressed data if the space between the previous and next compressed stream is equal to the uncompressed chunk size.