As French troops prepared to face Ottoman forces in Rosetta, Egypt, in July 1799, they stumbled upon a chunk of carved stone. Stuck into the wall of a fort, it displayed three languages — and ...

TL;DR: Study 25 languages at your own pace with a lifetime subscription to Rosetta Stone, on sale for $148.97 (reg. $399) until December 8 at 11:59 p.m. PT. Want to learn French? How about Spanish?