Inertia is a client for Second Life and similar services based on Snowglobe trunk, and includes patches from Henri Beauchamp's Cool SL Viewer and SLPE which are edited to be compatible with snowglobe 1.4 trunk.
This viewer will likely not interest most users of SL, and aims to include features useful to those debugging Second Life and those curious about its inner workings.
All code written by myself or other committers, unless otherwise specified, is licensed under the WTFPL V2 license. It may be included in any other piece of software without restriction.
I code for the sport, and it wouldn't be any fun to play against an open net, would it? The lindens are welcome to (actually, I'd expect them to) fix any bugs or exploits exposed in the Inertia source. The open-ness of the project also allows maintainers of similar projects (such as OpenSim) to fix any issues that may affect them as well. The end result is that Inertia is quite similar to the Onyx project, but we value transparency and invite anyone to join.
No. The only "private" version that exists is code that will not be given out to anyone, and this would likely only be for exploits that have the potential to take down the entire grid, or something of similar seriousness. Despite it all, I'm not Neil, and I don't much care about money.
Contrary to what you may have heard from [x], neither Inertia nor any other viewer like NeilLife or CryoLife is illegal to own or operate. Using the features of these viewers to circumvent copyright protection and to illegally access computer systems, however, is illegal in most areas. Discretion must be exercised when using these viewers, as with any other tool.
You can't. If my word means anything to you, I can tell you that it doesn't.
The main distribution method for Inertia is the github repository, but binaries are released periodically. I would personally not recommend using the binaries if at all possible.
If you wish to get a current list of differences between the Inertia source and snowglobe 1.4 trunk pre-2.0, simply run a text diff between the two source directories.
If you really don't trust the source at all and don't want to look it over, there will be patches for individual features available a la Cool VL Viewer as soon as features are finalized.