My contributions to today's Firefox release

Today (12/20/2011) marks the release of an update for Firefox that brings improved JavaScript performance using Type Inference (making Firefox about 20-30% faster), among other great updates. I didn’t work on the JavaScript engine improvements, but I did contribute a couple patches for HTML5 videos and the Web Console.

“Dimming the lights” for videos

Starting today, we now have greatly improved the viewing experience of watching HTML5 videos. See this short screencast for a demo of the feature at work.

This feature is perfect for the next time you come across an HTML5 video and want to “dim the lights”.

Web Console

Another feature I helped work on was the Web Console. Firefox contributors have been working really hard to provide the best set of developer tools out there. What you see today is the foundation for the future (hint: the developer tools in future versions are sweet!). The Web Console is a great tool to use to watch network activity, test a JavaScript snippet, and view JavaScript & CSS error logs.

Let’s go through a short tutorial of the Web Console in Firefox:

1. Open the Web Console
   • On Windows and Linux, press Ctrl+Shift+K
   • On Mac OS X Lion, press Cmd+Shift+K (Cmd+Option+K starting in Firefox Aurora)
2. Click in the command-line part of the Web Console (the text entry area at the bottom of the console)
3. Type console.log(“Hello, web console!”)

Great! You’ve just used the Web Console to execute a line of JavaScript. If you’re looking for something even cooler that you can do with the Web Console, venture over to Frank Yan’s blog post where he talks about animating Firefox’s tabs using the Web Console. Firefox’s Web Console can be a great Swiss-army knife tool to keep in your back pocket as you navigate the web :)