using codemirror on websites i'm not hosting myself

Is it possible to use codemirror as editor in my browser on websites which don’t load codemirror modules?
Eg. assuming stackoverflow wouldn’t use codemirror, could I still use codemirror to enter my questions/answers?

Similarly, stackoverflow doesn’t use the vim.js. Currently, I type my questions and answers in (g)vim, and then copy and paste it into the webbrowser.

[And, of cause, is this possibly documented somewhere for non-js developers?]

You could set up a ‘bookmarklet’, a javascript: link that pulls in some scripts from your own server implementing this functionality, which you store as a bookmark.