Firefox 9 Beta Is Almost Ready, Here's What You Need to Know

Firefox 8 is being officially launched, which means Firefox 9 in the beta channel and Firefox 10 in Aurora won't be that far behind. We've already covered the big new features in Firefox 8, now here's a look at some of the features that are already in Firefox 9 or are in the works.

Firefox 9 has spent six weeks in the Aurora channel. It also spent six weeks in the Nightly channel, where most changes happen, so a lot of work has already been done on it.

All it remains now, for the final six weeks of development in the Beta channel is some feature polish and completing some of the things that aren't done yet.

For now, the big changes in Firefox 9 are under the hood, there's no spectacular new feature that will stand out immediately.

This doesn't make the changes any less important, in fact, they may have a big impact on the way you use Firefox.

Type inferring for JavaScript for better memory usage and performance improvements

One big update, that is still in testing but looking good, is type inference for the JavaScript engine. Unless you're a developer, the importance of that won't be immediately noticeable to you, but suffice to say, it should result in significantly improved memory usage as well as faster performance for JavaScript code.

JavaScript checking for Do Not Track header

Earlier this year, Firefox introduced the Do Not Track header, the ability to signal to web pages that the user does not want to be tracked as part of a targeted advertising campaign.

This option is available to websites via the HTTP header Firefox, but there are cases when this is not ideal, which is why the data is now available as a JavaScript object in the global namespace.

Chunked XHR

Another new feature in Firefox 9, soon to become beta, which is of more interest it developers rather than users, although it will end up benefiting the latter the most, is the ability to split (chunk) XMLHttpRequests so that data can start being used before it has finished downloading entirely.

PFS2 used for plugin update data

There are a couple of more features which are in the works, but which may not make in the final Firefox 9. One of them is the ability to check for plugins, both unknown and updated ones, against the PFS2 database.

PFS2 is a service which aims to maintain a database of browser plugins and make the data available to browsers over the web. It will be used by Firefox to see what plugins are needed to run certain types of content but also to check whether existing plugins need updated.

Firefox 9 should be landing soon in the beta channel and Mozilla should have a round up of new features so we'll know soon enough if there are any other surprise features included in the Firefox 9 Beta.