It has been said that features like "intellisense" or "autocomplete" are
difficult to implement for dynamic languages such as Ruby.

I'd be happy with an IDE that let me choose a .rb file per project, let's
call it "environment.rb" which would usually be a list of "require"
statements which would establish a run-time state that would be a fair
approximation of what classes and methods would be available to 90% of my
application.

I mean, sure, dynamic languages let us add/remove classes variable and
methods anytime we like, but during the first moments of my application's
startup I usually set up 90% of the classes that I will need during the
remainder of the program's execution.

Adelle.