cost £6 million to develop. On 23 August 2008, a new feature, Series Stacking, was announced. This feature was rolled out on 13 September 2008 and allowed viewers to watch previous programmes from selected series until the series had ended, with a limit of thirteen weeks after first broadcast. Not all programmes will form part of the stack, however. The BBC Trust permitted 15% of content to be offered as part of the stacking service; soaps, news bulletins and review-based programmes will not be stacked, nor programmes containing material of a legal nature, such as Crimewatch. On 19 December 2008, the BBC released, as part of the iPlayer Labs feature, iPlayer Desktop for OS X and Linux operating systems. This moved the download service away from the previous P2P-based distribution model and onto an HTTP download model. On 20 April 2009, the BBC incorporated high-definition streams and downloads of some content on the iPlayer. There are plans to roll out the HD streams to devices such as the Virgin Set Top Box but no date has yet been set. An iPlayer application for the PlayStation 3 was announced by Sony in August 2009 and was released on 1 September 2009 along with the Firmware 3.0 update to coincide with the launch of the slimline PlayStation 3. Another version of iPlayer was released in late 2009 as a 'channel' for the Nintendo Wii. This shows only low definition videos of BBC shows up to seven days after their release on television. As of 2019, this version is unavailable due to the closure of the Wii Shop Channel. On 28 July 2011, BBC Worldwide released an international version of the iPlayer. Speaking in 2012, Ralph Rivera, BBC Director of Future Media, said: "In the same way as the BBC has a role in making sure there is a healthy TV ecosystem, the BBC should be playing the same sort of role in the digital sector. It's part of why we have a licence fee." BBC Radio services delivered via iPlayer were relaunched on 8 October 2012 under the BBC iPlayer Radio brand. The rebranded service offered different functionality from the main iPlayer interface and a BBC iPlayer Radio smartphone app was also launched. On 26 September 2013, BBC iPlayer Desktop was replaced by BBC iPlayer Downloads, which was no longer based on Adobe AIR. On the same date, the BBC stopped making