Wikipedia
SageTV Media Center, now open source, was a proprietary, commercial DVR (Digital Video Recording) and HTPC (Home theater PC) software for Mac OS X, Windows and Linux. It requires that the host computer have a hardware-based TV tuner card. The SageTV software has an integrated Electronic Programming Guide (EPG) that is updated via the Internet. The program provides a television interface for DVR, music, and photos on Windows and Linux. SageTV Media Center typically records in standard MPEG2, making it possible to transfer recordings to laptops or other devices. It also has a built-in conversion feature to transcode files into other formats compatible with iPod, PSP, cell phones and other portable devices.
A "lite" version is commonly shipped as part of an OEM software bundle. Both the lite and regular versions offer a Java API.
SageTV Placeshifter allows the user to watch TV from any high speed internet connection, similar to the Slingbox. As of Version 6, the SageTV Placeshifter is available for Windows, Linux and Macintosh platforms. The SageTV Media Extender set-top allows other TVs to connect to SageTV over a home network. There is also the ability to use the Hauppauge MediaMVP with SageTV by purchasing a MediaMVP Client License.
On Saturday, June 18, 2011, Jeffrey Kardatzke, CTO & Founder of the company, announced in a SageTV forum post that his company has been acquired by Google and an official press release followed later that same day, and since then the SageTV products have no longer been available for purchase.
On Monday, March 9, 2015, Jeffrey Kardatzke announced that SageTV will be open-sourced "in the near future (i.e. months, not years)". Then a few months later, SageTV became open source, hosted on Github.