[saurik]

"Why your web framework should not adopt Rack API" by José Valim

http://blog.plataformatec.com.br/2012/06/why-your-web-framew...

"This blog post is an attempt to detail the limitations in the Rack/CGI-based APIs that the Rails Core Team has found while working with the streaming feature that shipped with Rails 3.1 and why we need better abstractions in the long term."

[masklinn]

Broken middlewares won't be any less broken now that before.

[blutonium]

They are less broken now. The Rails team put a lot of effort into fixing them in the past three releases.