The InFocus New Tab F1 tablet features specs which were solidly mid-range last year, but in the coming year we're probably going to see on budget tablets. It has a 10.1" screen with resolution of 1280 x 800, and according to the specs shared last month we're looking at a tablet with a 1GHz quad-core Allwinner A31 CPU, PowerVR SGX 544MP2 GPU, 2GB RAM, and 16GB Flash storage.
You can find photos of the tablet on the FCC website, including both external photos and a teardown, but you won't be able to find the user manual. Infocus submitted the user manual they wrote for the Android version of the tablet, and that won't do us much good.
Firefox OS is an operating system based in part on the Firefox web browser. Unlike Android, where the most important parts are developed and controlled by Google, Firefox OS is open source. New development is supported by Mozilla, but not controlled.
This OS has shown up on a smartphone here and there, but it's still relatively unusual to see a device running Firefox OS. I haven't seen it myself, but I do know how to find one. If you're interested in playing around with Firefox OS you might want to buy a ZTE Open smartphone. You can find them on Ebay or Amazon for under $100.
As you can probably guess from the price, this is a relatively underpowered smartphone (specs). It has a 3.5" screen, a single-core 1GHz CPU, and it is actually running an old version of Firefox OS. But if you want to explore the new OS without sinking a lot of money into the purchase (or installing it yourself on other hardware), this is would be a good way to go.