What it does:
- Removes the need to login if you just want to play offline or on a private server
- There's no check for an update, you're directly catapulted to the main menu or connected to a server
- Additional parameters (f.e. start as maximized window or loading of certain versions from different directories)
What it does not:
How does it work?
Please be aware that this launcher does not work with the 1.6 snapshots, the 1.6 release and any later versions.
Basically this is just mimicking the behavior of the official launcher, except that it removes the online authentication and the update process. I figured most of that out with Trial & Error, that's why it's looking a little bit crude and has debugging output all over the place.
Please consult the README for a thorough documentation on the software.