Opera desktop team has released a new snapshot build of Opera 12.50 ‘Marlin’ with many significant changes. This release, marked as Opera 12.50 build 1538, re-enables support for WebSockets which was disabled earlier due to possible vulnerabilities. The Opera 12.50 will ship with a new User Agent string with no U; token and language indicator. Webmasters can easily retrieve user’s locale from the Accept-Language HTTP Header.

The current and proposed UA strings of Opera are as:

Opera 12.01 >  Opera/9.80 (Windows NT 6.2; U; en) Presto/2.10.289 Version/12.01

Opera 12.50 > Opera/9.80 (Windows NT 6.2; Edition Next) Presto/2.12.363 Version/12.50

Three new extension APIs have been introduced in this new build: Screenshot API, Page Visibility API and Resource Loader APIs. Along with this, the URL filter APIs have been improved significantly. Moreover, many stable CSS properties have been unprefixed in this build including those for CSS Transitions, Animations and Transforms. The above snapshot build can be downloaded from here for Windows, Mac and Linux platforms.

Opera 12.01

An update for the stable channel of desktop version has been released recently for all platforms. This version, Opera 12.01, brings various stability and security fixes along with the fix for newly launched Outlook.com. The Outlook.com was not working properly in Opera 12.