There is also this one: http://portal.acm.org/citation.cfm?id=1198521 http://portal.acm.org/citation.cfm?id=1198521 Instead of RRR it uses RLE and gamma codes.

There is also this one: http://portal.acm.org/citation.cfm?id=1198521 http://portal.acm.org/citation.cfm?id=1198521 Instead of RRR it uses RLE and gamma codes. Oddly, I have found no comparisons between this approach and RRR. I would expect RLE to compress better, and it is also conceptually simpler, but I don't know how fast it is.