Mozilla has just released a new milestone version for their recuperating web browser. Firefox 20.0 offers – as with most new versions – a combination of stability improvements, bug fixes and HTML5 additions so you can browse the web with less hiccups. Although that sounds far from interesting, this latest stable release also introduces a few new features that are worth highlighting. Among them are an improved private browsing mode, a new download experience and the ability to close hanging plugins without the browser itself hanging.

Private browsing has been available on Firefox for quite some time, but in its previous implementation, enabling the feature meant having your entire browser session in private mode while everything else was put on hold. Now Mozilla promises the ability to browse the web "without saving any information about which sites and pages you've visited" on a per window basis, so you can have private windows running simultaneously right alongside normal windows. That's similar to how Google has been handling its Incognito mode in Chrome all along.

For those who are not completely familiar with private browsing mode, the feature lets users browse the web without leaving traces of visited pages, form and search bar entries, passwords, downloads, cookies and cached web content on the browser client. It's main purpose is to protect your privacy on shared machines but it could be useful for things like having two accounts for a single service opened simultaneously.

Aside from private browsing, the download experience is also getting some improvements with a new interface and download button next to the search bar that makes keeping track of active and previous downloads a little easier. Clicking this icon will still bring up a panel with the most recent downloads as usual, but during active downloads this button now changes into a timer bar that estimates the time left for the transfer to complete.

Finally there's the ability to close hanging plugins, without the browser hanging. This is self explanatory and a big relieve for the millions of us who have lost sessions over a faulty plugin. The new Firefox is now available for Windows, Mac and Linux.

For download links and the complete release notes, head here.