No, not that one, the programming language used by the Caste Project. (Click here for the Monorail page.)
As opposed to Ruby on Rails, this is designed to work with .Net. It was developed before Linq was released.
Here's a brief summary:
MonoRail is a MVC Web Framework inspired by Action Pack.
MonoRail differs from the standard WebForms way of development as it enforces separation of concerns; controllers just handle application flow, models represent the data, and the view is just concerned about presentation logic. Consequently, you write less code and end up with a more maintainable application.
Although the project name is MonoRail, we do not have any affiliation with the Mono project. MonoRail runs on Microsoft .Net 1.1, 2.0 and Mono.
One more feather to learn and stick in my cap.