Opera Software rolled out version 9.0 of its free Web browser across 25 languages on Windows, Linux and Mac OS X platforms. The release adds a number of major new features, including widgets and support for BitTorrent downloads.

Widgets are small mini-applications that typically run inside another program. The basic idea is to enable developers to quickly build useful applications with simple scripting languages like JavaScript and DHTML. Opera notes that its widget support can be used for multimedia, news feeds, games and more.

Features such as saved sessions, the trash can (to get those closed tabs back), notes and the ability to start exactly where you last closed Opera keep are included in the new version of the browser. Secure browsing is still the single most important attribute of any Web browser. By introducing the security bar to prevent scams like phishing and strengthening Opera 9’s pop-up blocker to weed out annoying or potentially malicious pop-ups, Opera gives users new options for safe browsing.

BitTorrent support will help Opera target those savvy P2P users who don’t want to bother with an external application for their downloads. Users are able to search for files on the BitTorrent network through integrated search functionality, which then would use Opera’s Transfer Manager software to handle the download. The move could anger intellectual property holders, however, who see BitTorrent as a boon to piracy. The technology is currently used almost exclusively for the illegal distribution of copyrighted material by end users, even thought it is simply a communication protocol that facilitates efficient distribution of very large files.

Opera 9 also includes tools to make it easier for sites to code for open standards. Built-in Extensible Rendering Architecture (ERA) helps developers make sure their sites work well on any Web-connected device. Opera’s browsers are built on the same core technology, making it easy to test once in Opera 9 and ensure compatibility with a variety of devices - from mobile phones to Nintendo’s Wii.

Download Opera 9.0.