Firefox gets Unreal, Epic Port Unreal Engine 3 to asm.js JavaScript…

Mozilla and Epic have teamed up to push browser technology to new levels. Putting Mozilla’s brand new asm.js JavaScript technology to good use by converting Unreal Engine 3 to the new flavour of JavaScript. Free of plug-ins or installation this latest version of Unreal Engine 3 runs natively in Firefox browsers, and it’s fast.

This new version of UE3 came to life during the Game Developers Conference, part proof of concept part technology demonstration this is a major milestone for browser technology, while also being an interesting journey.


Going back to their roots the Mozilla and Epic team embarked on an old fashioned code-athon to celebrate GDC, porting the entire Unreal Engine in just four days. When powered by caffeine based drinks and high-carb snack food almost anything is possible.

Epic Citadel demo in a browser.
Epic Citadel demo in a browser.

As the team set out on their journey, porting UE3 from C++ to asm.js JavaScript and WebGL the crowd grew.  With tasks assigned the team of coders set about their tasks.

Mozilla’s new toy us a two part solution to JavaScripts slothful performance. The asm.js code is a hybrid JavaScript that can be compiled into native assembly language. OdinMonkey is the other part of Mozilla’s new technology, converting the asm.js JavaScript into native assembly language.

For hours on end the team of coders tested and corrected code, using an OdinMonkey enabled version of Firefox, testing and fixing.  For four days this continued, through sleep deprivation driven hallucinations and that one coder that never stops talking they worked on.

With the conversion complete (in record time) Epic loaded their famous Citadel demo into the engine, job done. The completed product doesn’t require any browser plug-ins or software to be installed, like any other web page it just works. Not only does it just work but this one piece of code will be able to run in Firefox on PC, Mac, Linux and Android without optimization or change.

Just plain cool.

While the performance is half the speed of the C++ original it is still a huge improvement over standard JavaScript which is generally twenty times slower than C++. Here at Highpants we believe it is fast enough to produce saleable games.

Even though only 4 days were taken to complete the conversion we will all have to wait for the Epic demonstration. The demo should be available for public consumption in June alongside the release of OdinMonkey that will be included in June’s stable build of Firefox, Firefox 22.

The impact of asm.js and OdinMonkey on the software industry could potentially be immense, installation free cross platform development has moved one step closer to reality.

Reference: ExtremeTech
Reference: VR-Zone