Alpa is an open-source system for training and serving large-scale neural networks like GPT-3 simple, affordable, accessible to everyone. Alpa aims to automate large-scale distributed training and serving with just a few lines of code. Alpa was initially developed by folks in the Sky Lab, UC Berkeley. Some advanced techniques used in Alpa have been written in a paper published in OSDI'2022. Alpa community is growing with new contributors from Google, Amazon, AnyScale, and more.