Which came first, Facebook or JavaScript?

JavaScript came first, by 9 years. Brendan Eich wrote it in ten days for Netscape Navigator.

Side by side

Facebook

Facebook launched on 4 February 2004 restricted to Harvard email addresses, opened to other universities through 2004 and 2005, and to anyone over 13 with an email address in September 2006. It is six years younger than Google and a year older than YouTube. Its predecessor Facemash, which compared students' photographs, was shut down by the university within days in 2003.

JavaScript

JavaScript was written in about ten days in May 1995, shipped in Netscape Navigator 2.0 later that year, and was called LiveScript until December, when Netscape renamed it as part of a marketing deal with Sun. It has nothing to do with Java beyond some borrowed syntax. Standardisation as ECMAScript followed in 1997, and the language spent a decade being treated as a toy before it became the most widely deployed programming language in the world.