In an article aptly titled "Open source (almost) everything", GitHub co-founder and current president Tom Preston-Werner writes[0], "Don't open source anything that represents core business value."
He specifically mentions two examples of what not to open source:
Core GitHub Rails app (easier to sell when closed)
The Jobs Sinatra app (specially crafted integration with github.com)
Now, I'd find the argument really stretched thin if you were to tell me that a text editor is your core selling point. Where does a text editor fit into GitHub's overarching mission?
