The Second Life backlash is in full effect, thanks in part to an article in Wired (How Madison Avenue is Wasting Millions on a Deserted Second Life) by Frank Rose, a journalist who made the shocking discovery that people don't want to spend their free time exploring the 'Coke Pavilion' or the 'Quaker Oats Hall Of Dietary Fiber' or other marketing efforts in this new space.
Further, the article implies that the companies that've sprung up to build these spaces for marketeers for stodgy companies that want to be cool might be taking advantage of misplaced enthusiasm. Sort of like the web design houses and professionals that took advantage of all the suckers wanting to get in on the irrationally exhuberant Web boom of the 90's, which I seem to recall Wired Magazine being around for. They weren't around for the California Gold Rush, where the people selling the pickaxes and such were the only ones making money, but they sure milked that analogy for all it was worth then, especially as things started to really turn to shit.
But I'm not here to defend SL, Wagner James Au will do that at New World Notes. This entry is about LSL, the Linden Scripting Language, and if it's true that SL is abandoned, you can probably find a nice quiet place to do some experimenting with building 3-D shit and then giving it functionality, which is one of the fun 'anything is possible' aspects to SL that people like Frank Rose are missing when they aren't missing their own reflection in a mirror.
The LSL Portal is an obvious starting point (it's also an item in the help menu). The 'Scripting Guide' also under the Help Menu will be valuable as a reference (what are the arguments to that function?, that sort of thing), but as an intro, it's not so great. In fact, the intro caused me to completely lose interest in the idea of doing anything with LSL for months, until it crossed my mind again.
Actually, probably the best intro I found was this tutorial at the Kansas Board of Regents. As most people in the other 49 states can imagine, I was really shocked to discover I could learn something from the state of Kansas, but this guide is a nice intro to many aspects of scripting (particles, objects rezzing other objects, commands via chat, 'physics', etc), with examples. Of course there are millions of scripts on the wiki, but it's nice to get the info in a tutorial format.
As far as tools go, aside from the editor inside the SL client, there's an Eclipse plugin for scripting, which could prove to be handy for some off-line editing. There's also an LSLEditor which gives the developer a very rudimentary framework for debugging, however, there's really no substitute for trying out scripts in the 3D environment where you can interact with the objects you are scripting.
Finally, a particularly good sample script (set of scripts actually) is the sailboat library. Sailing is popular in SL as it is not whiplash-fast, but still requires skill since you are at the mercy of SL weather patterns, and can't just point in the direction you want to go and accelerate. Anybody can take these scripts as a starting point for building a sailboat of their own. For an airborne version, you can build a balloon or dirigible with your mind, or create robots which do bizarre stunts, or fireworks and the like with llParticleSystem, or whatever. The 'build it yourself' nature of SL is as I mentioned earlier both a really cool (because there's a ton of potential, and people do make some cool stuff) and horribly aggravating (people make some really hokey shit - scientists call it the 'MySpace Effect') aspect of SL, something marketeers have not figured out how to tap into or incorporate into a marketing effort at all (to be fair, it's not a trivial problem, or somebody would have figured it out by now). Anyhow, have fun, just don't create grey goo, scripts that hassle people, or the like, nobody needs that.