No, there is another one called JPCSP. It's not very good, from what I've heard, but it looks like it's in alpha/beta.
It will stay on sale until selling it is no longer profitable.
What do you mean by works?
Has the best compatibility but
is being actively developed and is rapidly improving.
edit: It turns out that PPSSPP actually runs quite a few games way better than JPCSP, which is awesome. It even runs a few that JPCSP can't run, which surprised me. Still some games only run/run better on JPSCSP so do some research if you are having trouble with a particular game.
Clearly Wikipedia isn't looking at their code repositories or checking out their nightly builds, which you can find on emucr.com or http://jpcsp.org/. It's at least as active as PPSSPP is these days and it's the only PSP emulator that's usable at this point. I can't get anything to really play in PPSSPP yet whatsoever. Meanwhile I'm playing Wipeout Pulse at the highest speed at 60FPS at 720p with 3x native resolution with JPCSP's latest builds.
I can't wait for PPSSPP to come anywhere near JPCSP so that I can dump Java, but man... it's at least a year or two behind at this point. The release mentioned on Wikipedia is over 2000 changes behind.
(By the way, http://emucr.com is a good place to go to get precompiled nightly builds of all sorts of emulators, including JPCSP and PPSSPP. When changes are made, they push out new builds.)
Last time I tried it seemed to work fine on JPCSP.
Maybe it works on PPSSPP as well. The official 0.8 version will be out soon on that site, but you can also get automated builds from here: http://buildbot.orphis.net/ppsspp/