Ruby: MRI vs. REE vs jRuby vs Rubinius, for starters.

And this choice is solved through a variety of mechanisms that people rely on for other parts of their infrastructure, and feel strongly about.

For my part, this is also a solution that is way too late: We have Docker/Rocket and a range of similar tools. Why do it yet another way, when if you instead build a Docker image, you can take that Docker image and deploy it without having to translate your dependencies to a different format and re-test everything?

Docker is a wrapper around Linux. Vagrant is a wrapper around the entire VM [e.g. Virtual Box or VMware]. Thus Vagrant can be used to manage Windows environments. See the list of Vagrant boxes here:

http://www.vagrantbox.es/

Docker can wrap KVM/Qemu, so you can in fact use Docker as a wrapper around the entire VM...

But I take the point - the idea that anyone deploys stuff to Windows is just so foreign to me that it didn't even occur to me.

As far as looking alike goes I think it could end with uses Ruby or uses PHP. A lot of modules will differ for different use cases. I may not need any of the modules another user needs.

nothing about mentions installing modules for you. This is about the environment, not the actual project

PHP/Apache modules, which are very much environment based.