The short story is that animal trials of a vaccine have been completed and they're looking for funding to go further.
https://pledge.immunityproject.org/the-free-hiv-aids-vaccine
Discussion on Hacker News here: https://news.ycombinator.com/item?id=7108684
A few personal notes:
My first thought on seeing this was "I want to donate, but only if it's actually going to pan out. Otherwise it'll be a waste of my money." But that's exactly the wrong way to think about science. You fund it because it has a worthwhile probability of success. Even if the attempt fails, I can still believe that I've made a "correct" decision.
I've basically outsourced my vetting of the worthiness of the endeavor to Paul Graham, Sam Altman, and the rest of the YCombinator team. They have the time and the resources to examine and consider this more thoroughly than I could possibly do.
Another reason that I donated to this was to encourage the general idea of crowdfunded science.
Have they released the specifics of these discoveries? I couldn't find them anywhere on their web site. Given their professed goals, it's hard to see a legitimate reason not to do this.