Careful now, GIF uses Lempel-Ziv-Welch or LZW, which was patent encumbered in the US until 2003, and a few other countries until 2004. Not all Lempel-Ziv compre

Careful now, GIF uses Lempel-Ziv-Welch or LZW, which was patent encumbered in the US until 2003, and a few other countries until 2004. Not all Lempel-Ziv compression algorithms were patent encumbered though: LZ77 with Huffman coding is the DEFLATE algorithm which is very widely used, since that's the algorithm used in PKZIP/gzip/zlib.