Theano
An early Python library for numerical computation, a competing machine learning framework mentioned relative to TensorFlow.
Common Themes
Videos Mentioning Theano

The End of Finetuning — with Jeremy Howard of Fast.ai
Latent Space
Mentioned as an early deep learning library, along with its rapper Lasagne.

François Chollet: Keras, Deep Learning, and the Progress of AI | Lex Fridman Podcast #38
Lex Fridman
An early deep learning library that François Chollet used and ported Keras to, before TensorFlow gained dominance.

Jeremy Howard: fast.ai Deep Learning Courses and Research | Lex Fridman Podcast #35
Lex Fridman
An early deep learning framework that fast.ai initially used, but found harder to teach and research with due to its computational graph definition.

Rajat Monga: TensorFlow | Lex Fridman Podcast #22
Lex Fridman
An early numerical computation library that influenced the development of deep learning frameworks.

Guido van Rossum: Python and the Future of Programming | Lex Fridman Podcast #341
Lex Fridman
An early Python library for numerical computation, a competing machine learning framework mentioned relative to TensorFlow.

MIT 6.S094: Introduction to Deep Learning and Self-Driving Cars
Lex Fridman
An older deep learning library with a Python interface, one of the first to support GPU, and encourages lower-level tinkering.

Deep Learning for Computer Vision (Andrej Karpathy, OpenAI)
Lex Fridman
A Python library for defining, optimizing, and evaluating mathematical expressions, especially large ones, commonly used for machine learning.

Torch Tutorial (Alex Wiltschko, Twitter)
Lex Fridman
A Python library for defining, optimizing, and evaluating mathematical expressions, especially those with multi-dimensional arrays. It has a strong research focus.

Sequence to Sequence Deep Learning (Quoc Le, Google)
Lex Fridman
A deep learning framework mentioned for auto-differentiation.