While discussing with JP Boodhoo why he stopped to use the I notation for the interfaces, I think we got to the point where it was clear why would someone drop the "I" or opposite, adopt it. As a developer, I want to differentiate between a pure abstraction and a concrete thing. So to ease on ourselves...

Lately I am paying more and more attention to aspects of Domain Driven Development (DDD), development where code is looking more at the domain in which it is trying to resolve problem(s), rather than technologies it is using. One of the biggest headaches that you getting into when trying to adopt DDD...