A central place to find docs, guides, videos, PPTs related to Aura.
In-Org Reference App
Aura on the platform comes with a reference app that runs inside Aura enabled org itself! See here for more details: In-App Reference App
Aura Open Source Git Repo
https://github.com/forcedotcom/aura - Aura open source git repo. This runs on Java (not Apex) and you can use this for development or in production in your own data center.
Aura Open Source Developer’s Guide
https://github.com/forcedotcom/aura/blob/master/aura_oss.pdf - This shows how to install a Java Server and run Aura on it. Then goes over details of Aura open source development.
http://documentation.auraframework.org/ - Hosts detailed reference docs generated out of Aura source code.
Aura Dreamforce Video
https://www.youtube.com/watch?v=hYPTlCoKvmo - Listen to Aura’s main engineer and PM discuss Aura.
Aura OSS v/s Aura on the Platform
Aura on the (Salesforce) platform is a more restrictive subset of Aura OSS and runs on Apex backend.