The Chronobreak FTC Code Library - a collection of useful code snippets, structures, and various other bits and bobs useful for FTC programming. Designed to be used with Android Studio, though might (?) work with OnBotJava as well.
CFCl exposes a bunch of different APIs designed to be used together, but if needed they can be used independently too.
The core of the CFCl ecosystem, these are designed to be easily pluggable and replaceable chunks of code to interface with the robot.
Modules are the lowest level, interfacing directly with the robot hardware itself. These include things like drive systems, intakes, and actuators. Generally the code inside of these is fairly simple, translating useful inputs into motor and servo outputs.
Behaviors are the next level up, depending on any number of modules and translating more complex inputs into commands to the modules. These tend to be more complex, sometimes relying on multiple sensor inputs at a time as well as providing an output.
Any action that a robot can make, designed to be chained together with other Steps in a StepSequence. Can be used either in Autonomous or TeleOp, based on need.
A simple way to use a bunch of Modules and Behaviors together.
Opmode integration with the other APIs listed here.