Want a quick introduction to DCI? First, it stands for Data, Context and Interaction. Those are the three fundamental elements of the DCI paradigm.

The key aspects of the DCI architecture are:

For more details, you can get a good start at Wikipedia:

For an even more laid-back introduction, have a look at these flicks:

A glipmse of trygve. Keynote at ACCU 2016, 20 April 2016, by James Coplien.
The DCI Architecture: Supporting the Agile Agenda, by James Coplien.
DCI: Re-thinking the foundations of object-orientation and of programming, by Trygve Reenskaug.
DCI in Practice, by Rickard Öberg.
DCI - How to get ahead in system architecture, by Andreas Söderlund.

Otherwise, please browse the site. There are documents, examples, and many more goodies to look at.

If you want to get involved, go to the Google Group object-composition. That's where the DCI people hang out to ask questions and discuss progress.