Some others I like:

rev, vipe, comm, bfr, xxd

Do you know of a good resource listing all of these?

The standardized ones are described in the Shell & Utilities section of POSIX:2008/SUSv4 online at http://pubs.opengroup.org/onlinepubs/9699919799/

Yes, Num command has a quick list: http://www.numcommand.com/doc/helpers.html

`ls /usr/bin/?? /usr/bin/???` can be interesting to skim through.

In the same vein of 'improvements over things everyone assumes you have to do with the more famous tool', we could say grep '^string' : look :: sort -R : shuf

Thanks to @climagic on Twitter, I recently learned that sort -R and shuf are not in fact the same thing. (sort -R doesn't actually shuffle...)

My point there was that besides being a true shuffle, 'shuf' also has an algorithmic advantage when you only need a few lines (similar to how lookup has an advantage when you only need a few).

look does a binary search and only works on sorted files, while grep '^string' works on any text file but would be slower.