Right, I don't think anyone would recommend using Cloud9 as in c9.io, but AWS Cloud9 (https://aws.amazon.com/cloud9/) is still a perfectly valid option and does get updates.
For my usage, AWS Cloud9 has turned out far cheaper since the EC2 instance shuts down when I'm not using it. I can actually keep it within the free tier, which is a long way from $20/mo I was paying before.
But if you have anything on there that you want to keep, doesn’t it charge you something?
I would think the lowest grade machine is the equivalent of $5/Mo.
In cloud9 I like to have a node machine, a python machine, a rails machine and one to experiment on the front end, one for Data science. Basically I want to muck about on a clean machine.