Repository

1.I searched in Google about the repository. And I found there is mercurial in the firefox configuration feature and there is also mozilla github. I don’t know what’s the difference, though they do same repository functions.
2.Which items or software do Mozilla normally place under version control?

So… the main Firefox project is maintained using a Mercurial repository. Many of Mozilla’s newer projects, however, are on Github instead.

Nearly everything Mozilla does is in a public version control system somewhere. Which one depends on the project, what team is running it, and how old the project is.

Sheppy