JSPspEmu Git (2014/03/31) is released. JSPspEmu is a PSP emulator made using javascript (actually typescript). It will work with any modern browser. Though the first version work only works with Chrome (desktop and android). At this point it can run some demos.

JSPspEmu Git Changelog:
* - Updated project
* - Some refactorings
- Fixed elf allocation
- Added some stub functions
- Puzzle Bubble starts showing stuff
* - Passing a null pointer (value 0) to a string parameter in a hle function, should return a null string not an empty one
- Simplified struct definition
- Restored 0x4000 allocation after allocating elf (temporarily until relocation work better)
* - Fixed cpu_branch test (jalr set return address)
- Added SceKernelErrors
- Added more function stubs
- Added lots of new tests
* - Fixed big multiplications (mult/madd/msub/multu/maddu/msubu) (added Integer64 class)
- Fixed cpu's rotv
- Updated mocha to lastest version including support for promises
- Simplified tests using promises
- Improved pspautotests testing

Try online: JSPspEmu Git (2014/03/31)
Source: Here