Two days and fifteen years ago, Linus Torvalds posted a message on comp.os.minix:

I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones. This has been brewing since april, and is starting to get ready. I’d like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).

The operating system he was talking about became Linux, a major operating system that now runs on everything from cell phones to supercomputers.

Computer Science department of the University of Helsinki (where Linux was invented), and the Finnish Centre for Open Source Software will be celebrating the event on September 4th.