[benatkin]

It's called ack. Ubuntu gave its package and executable a different name because it conflicted with something far less notable (poor choice IMO). I suggest adding an a alias or a symbolic link so you can call it by its proper name when typing in commands.

[haakon]

Ubuntu didn't; debian did. Ubuntu just inherits that. Perhaps eventually they will fix it, which they did for git (which was once git-core because of a conflict with a less notable package).