Which came first, JavaScript or the World Wide Web?

the World Wide Web came first, by 6 years. Tim Berners-Lee wrote the proposal at CERN.

Side by side

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.

the World Wide Web

Berners-Lee circulated his proposal in March 1989, built the first browser and server by the end of 1990, and CERN put the software into the public domain in 1993. The Web is twenty years younger than the internet: the internet is the network, the Web is one service running on it, and email and file transfer both predate the Web by decades. The first website went live in December 1990 and is still online.