We use Neuron (
https://www.srid.ca/). Neuron also is available as a service (
https://beta.cerveau.app/) similar to ReadTheDocs (
https://readthedocs.org/).
All content is a markdown document (think 'portability' vs. alternative systems where content is more tightly integrated with the service).
MD docs are easily linked to build a network of ideas over time.
All instances are generated from our GitHub repos where different users can thread their collaboration on shared content.
We use Neuron as a staging area to collect cheatsheets, light-weight 'how to' instructions and blogs.
As ideas and cheatsheets 'take shape' we formalize them on a Sphinx platform (the same technology used by ReadTheDocs).
We're a Python shop, which is why we use Sphinx.
In our tests, creating and editing content on Neuron/Cerveau takes 70% of the effort of using Roam.
We use conventional editors (ranging from Atom to NP++; everyone has their own idea about 'the editor'); not EMACS or VIM. Some EMACS/VIM users seem to prefer other KM techniques that plug into those editors. NP++ and Atom both have MD preview panels.