The amount of useful material they have gathered is impressive.

- The Small C compiler set of articles, where you will get the sense not even K&R C was used outside UNIX for quite some time, only a common subset.

- The toolbox articles creating a Turbo Vision like framework in Object Pascal

- The evolution of Python and related adoption

- Strange programing languages like Actor, C@+ (try to search this one nowadays), Sather, BETA

- The fashionable compiler benchmarks that used to be quite common back in the day

- The evolution of C and C++ at ISO, while their standards were being started

- A more heterogenous way of software development, when it wasn't only UNIX clones and Windows.

https://archive.org/search?query=Dr.+Dobb%27s+Developer+Libr...

And the journals:

https://archive.org/details/texts?tab=collection&query=Dr.+D...