I, like most, hadn't even heard of Ruby before Rails. The two were synonymous - I remember having to explain to a number of people that should have know better that Ruby was a language and Rails was a framework.

I don't really know the history of Django but I'd wager it took a lot of inspiration from Rails.

Rails had that year's head-start on Django. By the time Django came along everyone was pretty deep into the development of Rails. I think it's mostly down to first mover advantage (it really did revolutionise web development).

In terms of frontend frameworks I have no idea what's going to happen.

Backbone definitely had the initial traction and it's nice and clean, but damn AngularJS makes development quick and easy. I've implemented things in the last couple of days in Angular that would have taken a week or more previously.

The Angular approach is unorthodox and seemingly inefficient but serves the developer well at the cost of CPU cycles.

Then again, I backed Prototype during the initial js lib battles and we know how that worked out.