The Atom Editor is a great hackable editor. Unfortunately it uses the default setting MRU when using CTRL+TAB to switch opened files (which is the wrong behaviour for me).

MRU (Most Resently Used) switches between the last accessed files in the very order they where used.

I don’t like that behaviour .. but as the editor is easy hackable I managed to disable/reset that setting.

Clicking on Edit > Keymap... opens a file named keymap.cson.

Appending the following few lines fixed the behaviour for me.

'body':
  'ctrl-tab ^ctrl': 'unset!'
  'ctrl-tab': 'pane:show-next-item'
  'ctrl-shift-tab ^ctrl': 'unset!'
  'ctrl-shift-tab': 'pane:show-previous-item'

Those lines are also easily removed once you want to test MRU again.