Roku's line of set-top boxes have been popular thanks to their simple controls, large set of available apps (recently expanded to include YouTube for the new Roku 3) and hardware ranging in price from inexpensive to downright cheap. Still, despite an active and encouraged developer community with custom channels and well-supported media player apps like Plex, the hardware has remained largely on lockdown -- until now. The GTVHacker team that previously unlocked Google TV and Chromecast has found a way to run its commands as root on any Roku 2 or Roku 3 using the most recent software version (unfortunately, that does not at this time include Sky TV's cheap Now TV player, which runs on older software). While the player overall is credited as "considerably more secure than others in the entertainment field" (Samsung comes to mind but it's from from the only one) a development password field provided a way in.
Full details here:
http://www.engadget.com/2013/12/28/roku-2-roku-3-rooted/