I agree that most tools that are similar are fairly easy to switch between: PHP/Python/Ruby/Groovy, and Java/C#/C++, all imperative, OO, etc. Also, from a tools

I agree that most tools that are similar are fairly easy to switch between: PHP/Python/Ruby/Groovy, and Java/C#/C++, all imperative, OO, etc. Also, from a tools standpoint, Rails guys can use Django and vice versa, pretty much the same, for sure. It also sounds like you agree that that's not so easily done with (quoting myself from above), "some programming languages/tools/methodologies." So sometimes, sometimes not. So... we agree? :P