Mozilla released Firefox 40.0 yesterday, and it brought a lot of new interesting features for Linux, including a few that haven't been publicized all that much. One of them is defaulting to the HTML5 video player in YouTube.

Mozilla was one of the companies that boycotted the use of Flash Player and added a warning in the previous version of Firefox. You could still use the Flash player, but after you accepted the fact that it poses a security risk. Since then, a lot of other online services have announced that they are dropping support for the Flash player, and it looks like it's finally going away.

With Firefox 40.0, Mozilla decided that it was time to push the Flash player out of the way and make the HTML5 player the default for YouTube. It sounds like a great idea, and it is in many respects. The only problem is that, from what I've gathered so far, only the 720p quality is available. All of the other quality settings don't show up in the options. It might be a temporary issue, but don't be surprised to find out that you can't get any decent HD video going.

Adobe Flash Player is terrible but supports full HD

Adobe Flash Player is full of security issues, and we're not sorry to see it go away, but it also feels like Mozilla is not making a big enough effort to make things work on Linux as well. The most important change in Firefox 40 is the compatibility with Windows 10, according to Mozilla. Stuff like 1080p movies in YouTube for Linux users is not really a priority.

I'm having this issue in Ubuntu 15.04, so it could be related to the operating system, but that's not likely. It's also worth pointing out that Canonical has been really quick to push Firefox 40 into the repository, on the same day of the launch, which has to be a première.