The Library is based off the Library in Rise of Nations, a game devoloped in 2004 by Big Huge Games; the same creator of DomiNations.
Originally, the Library'sTechnologies were organized into five categories, based off the categories of the Library in Rise of Nations. These categories according to the colors were Brown which represents Age, Red which represents military, Blue which represents civics, Green which represents commerce, and Yellow which represents Science. Over time, the amount of categories decreased from five to the official three in DomiNations.
In early stages of DomiNations, each Technology had three chapters. It later increased to four chapters in early 2016 and five chapters in mid-2016.