Cells is a Rails plugin to push things towards component-oriented architecture. Controller logic and views are encapsulated in lightweight cells and can be rendered like render_component.
Cells brings the benefits of component-oriented development to the Ruby on Rails web application platform, without the performance problems that had been associated with Rails' own, deprecated, component subsystem.
Cells behave like lightweight controllers with associated views.
Rendering a cell is similar to rendering a partial, but without the tight coupling to the controller that comes with partial rendering.
Besides decoupling views from controllers, a cell also implements business logic, thus pulling logic out of your controllers into flexible components that can be called from any view or controller in your application.
Cells brings components back to Rails, following a rich tradition lead by Apple's WebObjects and Smalltalk's Seaside. Now you can have the best of both page-oriented rendering, Ajax, and component-oriented abstractions with the beauty of Ruby and the power of Rails.