Wikipedia:Beta Cluster/Scope
The Beta Cluster on the Cloud VPS is a complete, production-like environment appropriate for final-stage testing of new features. It runs on git master and updates the MediaWiki core and extensions code every ten minutes. Beta Cluster is one of the Wikimedia test wikis, it has its own SUL login that is independent from production, therefore an account for en.wikipedia.beta.wmflabs.org will also function on en.wikisource.beta.wmflabs.org but not on any production wiki.
The full database of the Simple English Wikipedia has been imported, and it is the best place to test MediaWiki. You can also look at the site matrix to see all of the available projects.
Because the configuration files are shared with production, they may be seen at https://noc.wikimedia.org/conf/. Files in the beta cluster are suffixed with -labs.php
.