JSMESS – The JavaScript MESS (Multi Emulator Super System) ( Source).jTandy – Another JavaScript TRS-80 emulator.MC-10 Emulator – Emulator for the TRS-80 MC-10 microcomputer.jBacteria – The smallest JavaScript Spectrum emulator.ZX80 Emulator – JavaScript ZX80 Emulator.JSSpeccy – A ZX Spectrum emulator in JavaScript ( Source).Miracle – Sega Master System emulator ( Source).jsSMS – JavaScript Sega Master System & Game Gear emulator ( Source).jsbochs – Bochs PC emulator for the Browser ( Source).jemul8 – An object-oriented JavaScript x86 emulator for Node.js and the Browser ( Source).Virtual x86 – An x86 emulator written in JavaScript ( Source).JsDOSBox – JavaScript PC DOS emulator ( Source).n64js – An N64 emulator in JavaScript ( Source).mupen64plus – A port of the popular Nintendo 64 emulator for the Web ( Source).jsGB – A GameBoy emulator in JavaScript ( Source).fam – JavaScript NES emulator ( Source).XNES – Experimental JavaScript Super Nintendo emulators ( Source).Nezulator – A NES emulator in JavaScript.JSNES – A JavaScript NES emulator ( Source).IodineGBA – A GameBoy Advance emulator written entirely in JavaScript ( Source).GameBoy Online – JavaScript GameBoy Color emulator ( Source).GBA.js – Game Boy Advance in the Browser ( Source).CycloaJS – JavaScript NES Emulator ( Source).1964js – JavaScript port of the 1964 N64 emulator for Windows.pdp11-js – PDP-11 emulator with UNIX V6.PDP-11 Emulator – A JavaScript PDP-11 emulator.VICE.js – Versatile Commodore Emulator for JavaScript ( Source).VIC-20 Emulator – JavaScript VIC-20 emulator.SAE – Scripted Amiga Emulator ( Source).JSC64 – Commodore 64 emulator written in JavaScript ( Source).jsA8E – JavaScript version of the A8E Atari 800 XL Emulator.

EstyJS – A pretty fast and functional JavaScript Atari ST emulator ( Source).Apple2JS – A JavaScript emulator for the Apple II.

a2 – A fast, WebGL optimized Apple ][+ emulator.

Apple IIjs – An Apple ][ Emulator in JavaScript.

Roland – An Amstrad CPC emulator written in JavaScript.

CPCBox – Amstrad CPC emulator in JavaScript.

I’ve pasted the list below, but special thanks to Frederic Cambus who compiled the list. There’s a great list over at Github of about 50 emulators written in Javascript.

N64 emulator for mac 10.5.8