So I did some testing tonight and thought I'd share, just because i think its pretty cool. I set up my laptop running MoviePoster, running 2 local display views. Then configured it to run 8 other HTML5 displays, shown on various devices around the house. In the pic you can see from left to right, an older ChromeBook, my ThinkPad (running windows7, one portrait window, one landscape window), a newer chromebook, and a Black Friday special android tablet. Also, running off the same 'server' session are a few devices you can't see. A chromecast, a Samsung Galaxy Tablet, and a few display sessions running in a chrome browser. For a total of 10 MoviePoster displays, all running ff the same 'server' session on my laptop.
and with trailers playing... (Went to see Deadpool tonight. Great movie, but don't take your kids.)
Some findings about the HTML5 display so far; ChromeOS devices seem to work pretty well. Older, single core android devices do not work very well, but even a modern cheap multicore android tablet seems to work fine, Chrome browser tends to work best, firefox is ok, but might need some tweaks as it doesn't always apply rotation settings correctly. Safari, doesn't work very well. Smart TV browsers generally don't work well, and usually don't support full screen. the PS4 browser doesn't work all that well (scripts stop). the image crossfade is smooth on some devices but not on others, I'm not sure why. A large number of active HTML5 displays, even playing trailers to all of them, seems to have a minimal impact on performance of the 'server' machine, at least on my thinkpad (i5,8gb,ssd). I didn't have a linux machine or raspberry pi available for testing, but I suspect it will work fine if you use a modern browser, such as chromium.
One of the logical next steps is to allow for showing different posters on each display. In fact, the groundwork for this is already in place, but likely wont be i the March release due to lack of time for adequate testing.