PCE.js runs classic computers in the browser. This is a demo of PCE’s classic Macintosh emulation, running System 7.0.1 with MacPaint, MacDraw, and Kid Pix.
http://jamesfriend.com.au/pce-js/
This simulation is configured for a clock speed of 4.77Mhz, with 256Kb of RAM and a CGA display, using the original IBM PC Model 5160 ROM BIOS and CGA font ROM. This PC XT configuration also includes a 10Mb hard disk with Windows 1.01 pre-installed.