The 2.0 release isn't particular exciting technically, but I think it's a good time to promote the extension, and more generally the features behind X-Wikimedia-Debug.
- How to install it.
- Using it to capture verbose logs in Logstash.
- Using it to capture an XHProf profile and view it in XHGui.
- Using it to simulate database read-only mode.
See also T45086.