[[File:Jsmess in Chromium.png|thumb|upright=1.3|JSMESS emulating a CPC6128 in Chromium 30 on Linux (with copious debug messages)]]
[[File:Jsmess firefox zoomed.png|thumb|upright=1.3|Running in Firefox 24 (same rendering resolution but using page zoom)]]
'''JSMESS''' is a JavaScript port of [[MESS]] that runs in modern web browsers like Chrome and Firefox and is considered to be in its public beta stage right now.
==History and development roadmap==
Also, keymapping and a virtual keyboard on the screen are planned for JSMESS, although in principle you should already be able to create keymaps in MESS and use them with JSMESS.
JSMESS development is heading toward its 1.0 version. The [https://github.com/jsmess/jsmess/wiki/JSMESS-v1.0-Systems list of systems] that are supposed to be officially supported by 1.0 also includes the CPC464/664/6128 (although the printer is erroneously listed as the program medium for the CPC on the list).
==Building from source==
==Features and status==
As of October 2013, sound only works in Firefox and not in Chrome/Chromium. Emulation speed in Firefox is better than in Chrome, presumably because Firefox has better support for Emscripten's asm.js-based JS code. Internet Explorer 10 was supposedly supported very well by earlier versions of JSMESS with up to [https://github.com/jsmess/jsmess/wiki/Status 100% emulation performance] (including working sound) but the current JSMESS exits with an Emscripten error in IE 10. The joystick is mapped to Alt and the arrow keys by default.
==Usage on web pages and CPC demo page==