Update July 5, 2012: See this blog post for an updated test app and support for Grails 2.0+.
I released a new Grails plugin today, app-info. This plugin exposes a lot of internal information for a Grails application. Most of the code for this plugin dates back a long time and was originally mostly JSPs that I would copy into whatever application I was working on to give myself a view into what’s going on. Over time as I started using Spring and Hibernate I added more pages to display that information, and it now also shows information about Grails too.