"I would like to make you all aware of some very exciting news," Plex developer Tyson Edwards wrote in the official forums. "Microsoft has approved the development of a Plex Client for Xbox One."
There's no word on when it will be released but Edwards stated that it will be out "as soon as it is ready."
Plex was granted membership into Microsoft's ID@Xbox program that allows indie developers to self-publish games to the Xbox One. Microsoft has obviously expanded the program to include applications as well which opens some interesting possibilities for the console.
Currently, the Xbox One can only stream videos and music from a computer in the same house by using the "Play To" feature on Windows 7 and Windows 8 and is not fully DLNA compatible. The PS4 is not DLNA compatible either though and does not support the "Play To" feature. However, the Xbox 360 and PS3 are DLNA compatible and allow users to browse for movies on a local PC through the console and supported DLNA-compatible software such as Plex and PlayOn.
Microsoft's Larry "Major Nelson" Hyrb reportedly stated in January that DLNA support would be coming soon to the Xbox One.
For those that don't know, the Plex server software is installed on the computer that you want to serve as the host for your videos and music. You can then use a DLNA compatible device or the Plex client software for tablets, phones, Roku, Amazon Fire TV and now the Xbox One to stream video and music.
There is "nothing to announce yet" for a PS4 version according to Edwards.
Update: The first sentence has been changed to clarify that this is being made by a member of the Plex community and not an official app from the makers of Plex.