Opera 11 is the latest version of this popular browser, which adds a major new feature - support for extensions.
And there are a few extensions available already: a YouTube video downloader; a web page translation tool; something to display your Facebook stream at a click; a weather forecaster; a simple NoScript-type tool to prevent external scripts from running, and one or two others.
Installing an extension is extremely easy. Just head along to the new Opera Extensions page, find the extension you like, click Install, and the add-on is downloaded, installed and ready to use immediately - you don't even have to restart.
And if you change your mind later, a new Extensions page (Menu > Extensions > Manage Extensions) will display your current extensions, and let you disable or uninstall any that you don't need.
Opera has always been one of the fastest browsers around, and this version has been tuned for even better performance. There's now an option to make Flash or other plug-in based content load only when you click on it, for instance, which could seriously speed up the display of complicated pages.
Opera 11 also extends its HTML5 capabilities this time around, with support for server-sent events allowing a remote server to push content and notifications to you.
And there are plenty of other interesting additions elsewhere. A new bookmarks bar provides easier access to all your favourite sites, for instance, while you can now create folders that will keep your mail and RSS feeds properly organised.
Note that this is the portable version.