Built-in email, calendar and contacts applications and new Android apps are now available to BlackBerry PlayBook users, with the release of a long-awaited operating system upgrade from Research In Motion.

The PlayBook OS 2.0 became available for download Tuesday, filling in many of the key features that were missing when the seven-inch tablet was released by the Waterloo, Ont.-based company last April.

The original lack of native email and the shortage of basic apps such as video conferencing software drew widespread criticism from analysts, who called it "unfinished" and "half-baked."

Until the new upgrade, the PlayBook needed to be connected to a BlackBerry smartphone in order to access email, calendar and contacts in the absence of a Wi-Fi connection. That made made it unattractive to many consumers compared to competitors such as Apple's iPad.

David J. Smith, RIM's senior vice-president of mobile computing, highlighted some of the new operating system features in a post on the Inside BlackBerry blog:

A unified inbox for multiple email accounts, a contacts filing system that combines information from social networks such as Facebook, Twitter and LinkedIn, and a calendar that pulls information from social networks.

A feature that lets users use a BlackBerry smartphone as a remote control for the PlayBook during presentations or while using the PlayBook to connect to a TV.

Open On, which lets users open documents, photos and links from a BlackBerry smartphone onto a BlackBerry playbook with one click.

The company said it is also adding thousands of new apps to its BlackBerry App World store, including some Android apps that will run on the PlayBook.

Social Media BlackBerry fans cheer PlayBook OS update

It is also launching a video store in the United States. The company said it plans to add video store support for other countries later this year.

The company announced in January that the new upgrade was on the way for February. At that time, it got positive reviews and some analysts said the upgrade would make the device more competitive. But others suggested the new features were "too little, too late."

As of December, Research In Motion had shipped about 850,000 PlayBook tablets — fewer than analysts expected — and many were sold by retailers at a deep discount. As a result, the company said it would write off much of its PlayBook inventory and book a $360-million after-tax charge.