If you’re using a recent version of Safari, Chrome, or Firefox here’s how it works:
The basics should all work:
TAB to indent,
Shift+TAB to unindent,
Command+/ (OSX) or
Control+/ (Win/Linux) to comment out or uncomment a line.
While we try to guess whether your file is using tabs or spaces and the indentation level, you can set those yourself using the options in the top right of the editor view:
If the file you’re editing is Markdown, Textile, or any other richtext format GitHub supports we’ll render a preview of it instead of a diff:
If your favorite language isn’t being highlighted, consider adding a mode for it! Check out Ace’s “Creating or Extending an Edit Mode” wiki page for more info.
This is just the start. Help us make editing on GitHub even better by forking and improving Ace at ajaxorg/ace.
As always, please email firstname.lastname@example.org with any bugs you find or ideas you have. Happy hacking!