The download version of BBC iPlayer is now available for Mac and Linux users.
The BBC has worked with Adobe's AIR developer platform to create a desktop download manager for its online on-demand TV service, meaning users can now watch BBC content whether they are on or offline.
The beta version is now available to members of the BBC iPlayer Labs testing group with a full rollout expected early next year.
Although a download version of iPlayer has been available since its initial beta launch in July 2007, it was compatible only with Windows XP and Vista. A streaming version for Macs and Linux was launched around a year ago.
The BBC was criticised last year for the Windows-only way iPlayer was launched, with disgruntled non-Microsoft users creating a 16,000 signature e-petition urging the government to put pressure on the BBC to produce a multi-platform iPlayer.
Speaking to ZDNet UK's sister site, silicon.com, head of digital media technologies for the BBC Anthony Rose said the reason for the delay was the lack of a developer platform that would support DRM for Linux, Mac and Windows.
According to Rose, it wasn't until the BBC had access to Adobe AIR for Linux that it was able to develop the new download application for other platforms.
Adobe technology is "not only cross platform but actually powers very cool new propositions going forward", he added.
These propositions will start to appear in the first quarter of 2009 and are likely to include programme alerts, HD, podcast downloads and a pre-booking system whereby users can select a series to download in advance, a function already offered by the likes of Sky +.
"Really this is all about not only being cross platform, which is a fantastic immediate win, but it's all about a longer time win that we can produce a convergence between the web and your local desktop experience," Rose said.
The original download application was developed with technology from Kontiki and Microsoft but it will be phased out and replaced with the new cross-platform application launched this week.
The Open Source Consortium (OSC) was one of the most vocal groups about the lack of a multi-platform iPlayer when it was first released.
In response to today's news the OSC said it is "pleased to hear the BBC announce a new download player that is less restricting than their original release, and hope and expect that this heralds a new direction for the benefit of all licence-fee payers".
Since its launch, iPlayer has found its audience growing substantially, notching up more than one million programme requests per day during November and 237 million programme requests in total since the June 2007 launch.