CANADA, February 22 --- After delays of almost a year, an upgraded operating system for the Blackberry Playbook tablet has been released. Playbook 2.0, a free upgrade, adds a built-in email function to the device which was first launched in April 2011.

Canada-based Research in Motion (RIM) had promised the upgrade within 60 days of the device's release. Last month the company's co-chief executives stepped down amid faltering sales figures.

Mike Lazaridis and Jim Balsillie were replaced at the helm of RIM by the company's chief operating officer Thorsten Heins. This upgrade for the Playbook - RIM's first foray into the tablet market - also sees built-in calendar and contacts functions added, as well as tighter integration with social networks such as Twitter and LinkedIn.

source: bbc.co.uk