Spring RTS Engine

Hi, I'm a osx 10.8 user, and I download the engine manually.
Then I found I have no way to run it. After search the forum,
I found I can use web lobby.
But download in web lobby seems not working (firefox22),
anyone has any idea? Thanks!

I download spring the program, and can open it, but don't know how to load game and map;
Then I'm using weblobby, it cannot download game or map or engine.
So is there a tutorial for this?
Thanks.