I'm using the free Komodo Edit 5.2 editor, which I really like. The ActiveState website says this:

"Komodo is now built on the Mozilla 1.9 branch, the same code base Firefox 3.0 is built on."

Does anyone have a short explanation as to what the "Mozilla 1.9 branch & code base" is? Tried Wikipedia, but didn't find an answer.

Thanks,
Dave