A short while ago, Opera Software released Opera 11, which finally introduced extension support the venerable desktop browser. Soon after launch, the extension gallery went down, so I wasn’t able to preview the extensions in my earlier article. Fortunately, Opera sorted out the issues quickly and the gallery is back online.

As mentioned earlier, extensions for Opera are simply web applications that adhere to the W3C Widget specifications. They are developed using existing web technologies, and interact with the browser through certain methods made available in the API. Opera expects their implementation to be secure and fast. In fact, all extensions submitted to the gallery will be checked to keep out the buggy and malicious ones.

Extension Installation

Installing as well as uninstalling extensions is a breeze. Like Chrome, Opera doesn’t require a restart for either installation or uninstallation. However, users upgrading over an existing installation should note that extensions don’t seem to get installed properly, if you are using a modified toolbar configuration.

Notification of Installation Completion

Extensions might or might not have a user interface. If the extension has a user interface, it is generally exposed through a button that brings up an overlay screen. The buttons can update themselves dynamically based on the context. For example, a reddit extension button can display the number of upvotes the currently open page has received. Installed extensions can be managed through a dedicated Extensions tab that can be opened from the Opera Menu. Surprisingly, there isn’t any panel for extensions. However, this will be probably added in the future.

Opera 11 Extensions Tab

To kick things off, Opera is showcasing about fifteen extensions for Opera 11. However, in terms of quality, the showcased extensions are frankly all over the place. Some of them are useful, some of them are interesting for demonstration purposes, and some of them are a bit pointless. Listed below are some of extensions I found useful:

i) Fastest Tube – YouTube Downloader: This extension is very similar to the Download YouTube Videos as MP4script for Firefox, Opera, Chrome and Safari. It simply adds a download button to YouTube video pages (next to the embed button). You can download the videos in standard or HD resolutions in FLV as well as MP4 formats.

ii) Translate: This extension is quite obviously inspired by the automatic translation feature of Google Chrome. Whenever you open a page that is not in English, a notification will appear offering to translate the website to English.

Opera 11 Extensions: Translate

iii) Reddited: It adds a button for quickly submitting a page to reddit. If the page has already been reddited, it will display the number of upvotes the page has received and link to the submission.

Opera 11 Extensions: reddited

iv) miniFeed: This extension leverages the Facebook touch website to enable you to quickly check your Facebook stream and even post updates without having to open a new tab.

v) Opera to Phone: If you have an Android device (with FroYo), you can push any link from your Opera browser (for desktop) to the phone with this extension. Again, this functionality is quite obviously inspired by the Chrome to Phone extension provided by Google. In fact, it even utilizes the same Android app.

You can check out all the available extensions at addons.labs.opera.com/addons/extensions/. More extensions should start appearing soon. StumbleUpon and LastPass extensions are already under development. Don’t forget to share share your favourite extensions with us.