Mozilla is developing its own streaming dongle that runs Firefox OS.
The open-source device could be a direct competitor to Chromecast and Roku.
According to Gigaom, the device was supposed to be under wraps for a little while longer but was leaked on Twitter early.
Mozilla worker Christian Hellmann tweeted a picture of the device calling it “a fully open TV casting prototype device running Firefox OS. Open boot loader and all”.
The Mozilla streaming dongle is not only a competitor to the likes of Google’s Chromecast, but it can actually run some Chromecast apps.
There is currently no information on when Mozilla’s streaming dongle will be available or how much it will cost.
Mozilla recently announced that it will start selling a Firefox smartphone for just $25 – around £15.
The phone will initially launch in India and Indonesia.
Google's Chromecast was revealed last year and went on sale earlier this year.