It was created as a result of how useful Risugami?s RecipeBook is, but how quickly it became a hassle to navigate once you have a hundred pages at the time. RecipeBook has improved greatly since then, though. (In my opinion, the single greatest change was the addition of the scroll wheel as a way to navigate quickly)
To create your own, just place a crafting table in the centre of a crafting grid, put a piece of paper in each corner, and fill in the edges with four books. There is also a keybind to open it without needing an item (defaults to G), which works even if you are playing on a server that doesn?t have it installed (note: there isn?t a server version at all right now).
Other useful features include small recipes as well as shapeless recipes having a visually distinct bsckground. Additionally, you can click on an item in a recipe to filter the displayed recipes so that only ones that require or produce that item will be shown (In this case, books). Use the clear button to go back to seeing them all.
One of the more recent features is a searchable list of items, to quickly filter out unrelated recipes.
Just right click while holding it, to see every crafting recipe in the game.