The Silver Searcher, also known as Ag, is a clone of Ack written by Geoff Greer in C for speed. Ack is quite slow on large codebases since it uses Perl. I found Ag to be significantly faster on my code and switched to it.
Installing it is easy:
$ sudo apt install silversearcher-ag
Using it is similar to Ack:
$ ag foobar
To add a certain file to be ignored, add it to
# This is ~/.agignore someuselessfilename
Tried with: Ag 0.19.2 and Ubuntu 14.04