In a piece posted here some time ago, Works on My Machine, I offered some suggestions on how to ensure our local development environment doesn’t have leftover configuration from a previous project that might affect our current project. One suggestion was to use an online coding environment rather than adding more and more configuration settings to a longstanding local system.
I listed two such environments with the caveat that this was a relatively new option, and we should “[e]xpect to see these environments improve, and expect to see more players in this market.” One that I listed at the time was C9.io, which is very good. Since the piece was published, C9.io has been purchased by Amazon and is now commercial. If that’s okay for you, then great. If you’re looking for something free of charge and non-intrusive, I’ve come across a couple of alternatives:
Supports several languages, Github integration, Travis, and similar integration
Supports several Node.js frameworks for webapp development
Keep in mind this is a rapidly-changing segment, so keep your eyes open for even better alternatives as well as for changes in the “free” status of these services.