GameBoy Online is a Game Boy and GameBoy Color emulator written in Javascript. It strives to be efficient and try to have a perfect compatibility. Currently the execution speed is not optimal even on browsers. For example on Chrome, which is nevertheless deemed to run Javascript faster on a PC running Windows 7 64-bit version with a double heart 2 CPUs at 2.2 GHz, games run at normal speed but almost skipping some frames.

The sound production is still experimental and rather poor quality. The video portion is by HTML5 or by creating images with BMP string URI. State backups are implemented using the object window.localStorage and are serialized / deserialized JSON. Ditto for backup SRAM.



GameBoy Online Changelog:
- Cleaned up some audio handling code ( I noticed Firefox 6 for windows actually crashed in this code, while win 7 and mac did not, so I rewrote the trouble spot completely (Super weird, since it seemed to get caught on an impossibility.).).
- Some more cleanup.
- Making sure audio is neutral if disabled.
- Slight optimization.
- Made the white noise audio channel more accurate.
- Fixing the volume for the LSFR algorithm.
- Fixing a regression.
- cleaned up the LSFR caching code.
- minor update.

Play Online: GameBoy Online (2011/09/02)
Source: Here