fastai

Enables building state-of-the-art models like image classifiers and text analyzers with just a few lines of code, as shown in the Quick Start.

Provides a hierarchy of APIs from high-level productivity to low-level configurability, allowing deep customization without learning the lowest level, based on the layered design.

Features a novel two-way callback system that accesses and modifies data, model, or optimizer behavior at any point during training, offering fine-grained control.

Includes an extensible computer vision library written in pure Python but optimized for GPU performance, as highlighted in the key features.