Doug's digital footprint is rather large and spans 50 years. You can begin by reading his papers, from his original proposals from the 1960s to summaries from the 2000s. You can watch videos of his talks from the "mother of all demos" in 1968 to a 2008 tribute at Stanford.
In this section, I'll try to summarize the big ideas gleaned from Engelbart.
When I engage in "meta-work", it's often "C Activity" work. Also, building a framework like RedwoodJS or Croquet is very much "C Activity".
Of all of his papers, the two that have been most recommended to me are:
Talk: YouTube
Lots of interesting ideas in this talk. May need to watch it a few more times in order to really get it. Need to document more.
Other References: