No its nothing to do with drugs, or the human genome, or even X-rays (in the context of Tridion at least) – its the marketing lingo for the SDL Tridion Reference Implementation (STRI or TRI) – The Digital Experience Accelerator. This week Bart and I presented a bootcamp on this subject, and all the presentations are publically available

There is a lot of good content in here which will enhance what you have in the docs, so here are the presentations:

1. DXA HTML Design – how to work with and customize the HTML Design
2. DXA Web Application Overview – design principles underpinning the web application architecture/design
3. Responsive Design in the DXA – How the responsive design works client and server side
4. DXA Extensibility – some ways in which the DXA/TRI could change the way you do Tridion projects, and an overview of the main interfaces you can implement to extend Web Application behaviour (and use cases for this)

Enjoy!