Homebrew developer Virtuous Flame has apparently been working on a new popsloader and a build that's good enough to be released to the public has finally been reached.
The dev's fellow Team PRO member Coldbird notes that every POPS version ever released is supported in this build. Those who want to play around with the source code can find it at the source link below. Do note, however, that the posloader download page says that "You have to use the latest PRO nightly build to get it working(at least 658643515142)".
For those unfamiliar with it, popsloader basically lets you play PSOne games on your PSP without having to buy them off the PlayStation Store. You can just rip your old PSOne discs into ISOs. Before you can start playing, however, you'll need to dump and decrypt a few firmware files. More details on this can be found in the readme file included in the download.