JS source compression shows up noticeably when starting the email app (see bug 836515) In the quick measurements that I did, fast lz compressors tend to be about 10x faster and produce output that's about 1.5x bigger when run on minified js source. This is probably a trade off worth taking at least for single core cpus.

Here are some actual numbers from on ARM on gaia-email-opt.js time ./snzip -c /home/jrmuizel/gaia-email-opt.js > /dev/null real 0m0.123s time gzip -c /home/jrmuizel/gaia-email-opt.js > /dev/null real 0m0.737s size: snappy: 522077 gzip: 328346

If you choose to compress JS sources with Snappy, you may also want to fix bug 768074 (update our in-tree copy of Snappy to get their ARM optimizations).

now LZ4 it support also strems http://fastcompression.blogspot.it/p/lz4.html