On: Island Generator

[david-given]

See also the venerable xmountains (possibly already installed on your workstation).

Screenshot: https://osde8info.files.wordpress.com/2007/02/6a00d4141b9517...

There's a writeup on how it works:

http://www2.epcc.ed.ac.uk/~spb/xmountains/about_xmountains.h...

I don't know how old it is, but the timestamp at the bottom of the HTML file above is 1997.