system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: DRM in HTML5

The post that has been on the front page.
gpt
**First a little background.** Cue wibbly, wobbly, flashback scene.

For almost as long as the web has been around, people have wanted to playback video in webpages.  There were several attempts to achieve this: RealPlayer, Windows Media, but the ultimate king of them all is Adobe Flash.  Flash can playback video in many formats on virtually all web-enabled devices.  However, it requires you to have installed the Flash plugin for your browser but this isn't much of an obstacle since about 97% of PC users have done so.  So Flash became the de facto standard for video on the web.

Anyway, to cut a long story short, a bunch of people saw that Flash was the web video king and said, 'Hey, the web is supposed to be about open standards but *that* is proprietary and controlled only by Adobe'.  The irony is that one of the loudest to whine about the lack of openness was Apple, but that's a story for another ELI.  And so the HTML5 <video> tag was born.  This would build video support directly into the browsers and negate the need for any of this nasty plugin nonsense.  The world met the arrival of HTML5 with absolute silence, except for a few web developers who said, 'Hooray!' and slowly began updating their websites with the new technology.  

Except there was a problem.  You see, although the HTML5 standard tells you how to embed a video in a webpage nobody could agree on the format of the video file itself.  Some people, like Apple and Microsoft, said it should be H.264 - which is a good format but it requires the payment of a royalty to the patent owners.   Who include Apple and Microsoft.  Hey, at least they declared their conflict of interest.  As a result, both Safari and Internet Explorer only support video in H.264 format.  But Firefox and Opera, who were part of a group advocating a more open standard, are (sort of) boycotting it.  This means that a webpage has to include at least two video files (probably three) in order to be viewable on those browsers.  Chrome supports everything at the moment but the whole thing is a complete mess that, far from eradicating the problem it was supposed to have solved, has meant many content providers have decided to simply stick with Flash.

**So, back to the present.**

Microsoft, Google and Netflix have devised a plan to 'enhance' the current support for video in HTML5 by adding what they playfully refer to as 'encrypted media extensions'.  One of the reasons content providers are reluctant to move away from Flash player is that HTML5 video does not give them 'sufficient control' over their content - i.e. DRM.  The EME, though they aren't strictly DRM in themselves, will give them the tools to add proprietary DRM into certain web browsers and/or devices.  Of course, this means there will be other web browsers and/or devices that aren't supported.

**So why are people talking about it?**

The problem with DRM is that it requires software to function in ways that harm the users, for instance by deliberately disabling certain functionality.  This means that the software has to be written in a such a way as to only allow the user to do exactly what the content provider wants.  The free software movement is opposed to this on the grounds that it restricts the user's freedom and the open source community is against this because it is unworkable in practice (at least in open source software).  Power users are upset that they find themselves having less and less control over the computers and devices that they own and web developers are cheesed off that the thing that was supposed to put an end to the use of proprietary plugins is being turned against them.  However, the big corporations and content owners are really excited about it and, since money talks on the web, we can expect to see it rolled into the standard in the near future.

**TL;DR** - video on the web is a big mess that isn't getting any (much) better.  Embedding DRM into open source applications is practically impossible, which has led to this being interpreted as an attempt to lock certain browsers out of video streaming websites.