Just 3 things that come to mind, I don't know if that is what you are looking for. It is coming from more of a C# and Java angle, than a Ruby and Python angle.

Just 3 things that come to mind, I don't know if that is what you are looking for. It is coming from more of a C# and Java angle, than a Ruby and Python angle. * People like Robert "Uncle Bob" Martin popularising and extending the ideas of Bertrand Meyer with i.e. SOLID principles, and design ideas focussed on quality and maintainability. * Domain Driven Design, also in some sense a rehashing of old ideas but combined with some new ones as well. * Service Orientation and Component Orientation could both be seen as extensions of OO to higher level design and architecture.