Like Ruby on Rails, Merb is an MVC framework. Unlike Rails, Merb is
ORM-agnostic, JavaScript library agnostic, and template language
agnostic, preferring plugins that add in support for a particular
feature rather than trying to produce a monolithic library with
everything in the core. In fact, this is a guiding principle of the
project, which has led to third-party support for the ActiveRecord,
DataMapper, and Sequel ORMs.