JSPspEmu Git (2014/03/25) 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:
* - Added Memory.reset to clear screen display at least
- Added clut-related GPU commands (not decoding yet)
* - Fix alpha display
* - More work on shaders
- Added texture support
- Small additions
* Merge branch 'master' of github.com:soywiz/jspspemu
* Update README.md
* Update README.md
* Create README.md
* - Removed old js
- Improved gpu
- Added support for drawing sprites in webgl impl
- Added text.elf demo (no textures yet)
* - github static server doesn't like files starting with underscore
* - First commit

Try online: JSPspEmu Git (2014/03/25)
Source: Here