[res0nat0r]

Unix Rosetta Stone is also very useful: http://bhami.com/rosetta.html

[solidpy]

I've recently started using Arch and their Pacman Rosetta has helped me a lot, it has equivalences in package managers for all the popular distros: https://wiki.archlinux.org/index.php/Pacman_Rosetta

[ilurk]

And the Rosetta Stone of Performance Checklists:

http://www.brendangregg.com/USEmethod/use-rosetta.html