RailsAdmin vs. Massive

RailsAdmin is a Rails engine that provides an easy-to-use interface for managing your data.

Massive's goal is to help you get data from your database. This is not an ORM, it's a bit more than a query tool - our goal is to do just enough, then get out of your way. Massive embraces SQL completely, and helps you out when you don't feel like writing another mundane select * from statement.