Merb started as essentially a wrapper on top of mongrel handler. Merb = Mongrel + erb. Mongrel had concurrency and it was super lightweight. However, it did not

Merb started as essentially a wrapper on top of mongrel handler. Merb = Mongrel + erb. Mongrel had concurrency and it was super lightweight. However, it did not have goodies like routing or templating engine. Ezra write Merb as modular framework which did not care if you used datamapper or active record. Haml or ERB.