HTML5 video is native video for browsers based on the the <video> element..

Miro Video converter is an open source video conversion tool for Mac that makes it very easy to convert videos to all kind of formats via drag and drop.

Archive.org is a web site dedicated to archiving the internet. For content released as with a Creative Commons license it offers hosting for video and audio and automatically converts the content to MP4 and Ogg Video for you.

Vid.ly is a web service by Encoding.com which creates dozens of formats of an uploaded video in almost real time. Using vid.ly you get a single URL that redirects browsers and mobile phones to the format they support the best.

This is the source code of this demo on GitHub for you to fork and look at.

Popcorn.js is a HTML5 video framework that makes it easy to sync video with other page content.

Butter makes is easy to create portable HTML5 content that is synced with a video.