OK, this is going to sound rather dry and complicated. But bear with us, because what we're about to describe is actually very important for the future of the web.
A war has broken out over web video. Yes, we warned you, but bear with us.
Most video - and audio - on the web right now is displayed using Adobe's Flash plugin. This isn't ideal, as it makes the web very reliant on one company's technology and on software that's not built-in to web browsers.
So when the internet boffins were designing HTML5, the latest version of the code that underpins the web, they sensibly decided to agree a way to support video and audio without Flash. HTML5-compatible browsers, including the latest versions of Google Chrome, Microsoft Internet Explorer and Mozilla Firefox, let web developers embed video or audio in a page using a simple 'video' or 'audio' tag, just as they embed a picture using 'img'.
Still with us? OK. The problem is: which format can a video be coded in to work with the tag? For pictures, it's easy; all modern browsers can show JPGs, GIFs, PNGs and TITs (OK, we made that last one up).
Now, until recently, it was largely agreed on what video format would be accepted, too. HTML5 was to be all about H.264. This unfortunately-named format is as geeky as it sounds - in fact, it's the video format underpinning Blu-Ray video and some digital TV.
But it's not, strictly speaking, an 'open' format. You need a license to produce H.264 video, although licenses don't cost anything right now. But this isn't enough for Google. Last year, Google launched a fully 'open' video format, WebM. Now, it's decided that its Google Chrome browser will only allow the 'video' tag for sites using WebM, or the open-source alternative Ogg Theora (don't ask). H.264 is out.
Of course, WebM being made by Google, rival browsers like Internet Explorer and Apple's Safari don't support it. Meanwhile Firefox and Norwegian rival Opera don't support H.264. So we have something of a war going on, with Google siding with Mozilla and Opera supporting WebM, and Microsoft and Apple (old friends!) supporting H.264.
But Google, being Google, thinks it has a way forward - it's producing a plugin add-on for Safari and Internet Explorer that will make them play WebM. More than likely, someone will make an H.264 plugin for Chrome, and - whoopee! - we're back where we started, with everyone using a plugin.
Isn't the internet great?!