[andywhite37]

I think Git owes a ton of its success to github.com. Without this extremely well-designed, central repository for repositories, the uptake of Git would have been much slower, and faced much more resistance in the wild. Git is a great tool on its own, but having a centralized place for people to learn and use Git has been huge.

[imr]

In addition to github, you have the switch to git of the linux kernel which really put the project over the other distributed revision control systems such as Darcs and Mercurial.

[j_baker]

On the other hand, one could also attribute github's success to git's success. I suppose it's most likely symbiotic: github contributed to git's success and vice versa.

[michaelbuckbee]

That's undoubtedly true, but I wonder if the GitHub guys had picked up Mercurial instead if it would have grown as fast.

[lurker19]

It git or it github?