The two systems, which until now could only stream programmes from the iPlayer, will now be able to handle downloads as well.
The BBC has worked with Adobe to develop the new version, known as BBC iPlayer Desktop. It has been written using Adobe's AIR technology which aims to make it possible to create applications that can be downloaded to your computer, rather than embedded in browser web pages.
Those who want to try the new version can download a trial version from the Labs section of the iPlayer site. A finished version is likely to be released in February 2009, says the BBC.