Orbit is a flexible, lightweight library designed to make it easy to write custom training loops in TensorFlow 2. Orbit handles common model training tasks such as saving checkpoints, running model evaluations, and setting up summary writing, while giving users full control over implementing the inner training loop. It integrates with tf.distribute seamlessly and supports running on different device types (CPU, GPU, and TPU). The core code is intended to be easy to read and fork.