The curtain rises on Opera 9

Opera Software on Tuesday released the newest version of its popular browser, which is designed to offer several improvements over its predecessors.

Opera 9, which had been in beta since April, includes features designed to improve the efficiency of Web surfing, enhance security and allow users greater control over the content they view.

Opera 9 aims to allow users to relaunch their browser where they last left off, as well as block advertisements on a site-specific basis. Other content-related features include widgets, or small Web programs, designed to help users organise their browsing preferences, play games or follow sports teams.

A security bar has also been added to Opera 9, a response to the prevalence of phishing scams and identity theft. The security bar aims to reduce users' encounters with phishing scams and also includes technology to strengthen blocking of pop-up advertisements.

Opera 9, which is offered as a free download, runs on a variety of platforms, from Windows to Mac to Linux. It also supports BitTorrent's file distribution technology.

"For Opera 9, we worked hard to push the limits of what people expect from a Web browser," Jon von Tetzchner, Opera Software chief executive, said in a statement.

To read a review of the browser, click here. To see photos of Opera 9 in action, click here. A copy of the software is available at CNET.co.uk's sister site Download.com.