Strange that I can't find the word "match" anywhere on their site...
Not strange at all, it's their site and their design, and it wouldn't look aesthetically pleasing to add the word "match" in there. Sometimes style is more important than the visitors being 100% informed. In design less is more.
Gizmodo, a popular technology blog, posted this artice about SIAI. It's partly tongue-in-cheek, but also apparently thinks well of the Singularity Institute, claiming they are "a research organization that's as forward-thinking as most Gizmodo readers (read: sci-fi nerds)." More importantly, they link to Philanthroper, where you can donate and see your donation be matched. File this under "cultural penetration of Singularity memes" and also as a chance to make your donation more effective.
http://gizmodo.com/#!5787599/give-1-to-stop-terminators-seriously
Edit: Better link to the above URL