clksignal (emulator for various classic computing platforms)

CLK, also known as Clock Signal, is an emulator for tourists that
seeks to be invisible. Users directly launch classic software with no
emulator or per-emulated-machine learning curve.

It currently emulates the Acorn Electron, Amstrad CPC, Apple
II/II+/IIe, Atari 2600, Atari ST, ColecoVision, Commodore VIC-20,
Enterprise 64/128, 512K Mac/Mac+, MSX-1, Oric/Atmos, Sega Master
System, Sinclair ZX81/81, and Sinclair ZX Spectrum.

Through the combination of static analysis and runtime analysis, CLK
seeks to be able automatically to select and configure the appropriate
machine to run any provided disk, tape or ROM; to issue any commands
necessary to run the software contained on the disk, tape or ROM;
and to provide accelerated loading where feasible. The full process
of loading a title - even if you've never used the emulated machine
before - is therefore: 1. locate it in your OS; 2. double click
it.

Notes:

- clksignal requires ROM images for most of the systems it emulates.
  When an image is missing, it will tell you the name, size, and
  CRC of the image, so you can go search for it on the web.

- For the "locate and click" to work, you'll have to associate the
  file types/extensions with clksignal manually.