How to put application/x-mpegURL in source in videojs
Original, but now outdated answer:
For browsers without native HLS support you need the videojs-contrib-hls plugin: http://videojs.github.io/videojs-contrib-hls/
As of Video.js v7, HLS is supported by default and does not require anything additional in the default build. HLS playback is either native (Safari, iOS) or Video.js's Media Source Extensions playback engine https://github.com/videojs/http-streaming, which replaced videojs-contrib-hls.