These last few days, it seems that the extensions team has developed a newfound love for the F5 key. We all keep refreshing the "Most recent" page of our new gallery, obsessively checking the newest amazing extensions that developers have uploaded. Today, we get to share this nervous tic with millions of Google Chrome's users. We're launching extensions in the beta channel for Windows and Linux (Mac is in progress). We're also opening our gallery, which, as of now, contains more than 300 extensions!

An extension system has been one of our most requested features for Google Chrome. It's a tribute to Mozilla and the Firefox project that nowadays, users just expect all browsers to have built-in extensibility.

We started the project by presenting a design doc that outlined our vision to create an extensions system based on web technologies - a system that is easy to use, stable, more secure and that wouldn't slow down Google Chrome. It wasn't always easy to balance our goals, and sometimes we had to make tough trade-offs.

Since we built all of this in the open, we had tons of help. Developers started using our code shortly after the first check-in, and have been sending us feedback on our mailing list ever since. Being able to see the extensions people were trying to build and the problems they faced made it more fun to design the system, and motivated us to keep fixing the bugs.

Today, we're really happy to release a beta of extensions that begins to deliver on our initial vision. Extensions are as easy to create as webpages. Users can install and uninstall them quickly without restart, and extensions have a great polished look that fits in with Google Chrome's minimalist aesthetic. When developers upload an extension it is available to users immediately, with limited restrictions and manual reviews only in a few situations.

On the technical side, we've been able to use Google Chrome's multiprocess architecture to help keep extensions stable and safe. And Chromium's extensive performance monitoring infrastructure has helped us ensure extensions affect Google Chrome's speed as little as possible. You can learn more details about the internals of our system in the videos below.



We still have a long way to go - next up, we're going to be working hard to get extensions to all Google Chrome users, and we're already brainstorming the next set of API improvements. Oh and, we should also fix some bugs ;-).

For those of you who want to learn more about extensions, let us know if you want to join us in a small get together tomorrow in our campus in Mountain View. Space is limited - we'd love to see many of you there so do RSVP early and we'll email you more information if are selected to attend. You can also meet with our team at Add-on Con, where we are going to participate in a couple of panels. Finally for those of you who are far away, we are planning some online developer tutorial sessions. If you are interested in attending these, please fill in this form.

Posted by Erik Kay and Aaron Boodman, Software Engineers