Neither article links to the other. Are they the same? Different? Wholly different efforts?
vs.
Topic on Talk:MediaWiki-Docker-Dev
They link to each other now (as long as my edits aren't reverted). I was similarly confused, and still am to be honest. In favor of MediaWiki-Docker, I was able to follow their DEVELOPERS.md to easily get up-and-running. I would've stopped there, except the Docker environment that ships with MediaWiki core is SQLite-backed, and I wanted to be able to load in SQL dumps from MySQL. My Docker-fu is not that strong, so the search continues for other options. --Ernstkm (talk) 19:34, 18 October 2023 (UTC)
@Ernstkm See MediaWiki-Docker/Configuration recipes/Alternative databases for how to use MediaWiki-Docker with MySQL.
The first one is a development environment included with MediaWiki core and supported to some extend by various people in WMF, the latter is an independent initiative the predates the core environment. Both are in active development and there is collaboration between developers on both projects. MediaWiki-Docker-Dev is more fully featured, currently.