I tried editing a module today on Wikipedia, only to find that Safari for iPad 4 doesn't seem to recognise the Code Editor as an input field, hence the keyboard doesn't come up. I'm using iOS 7.0.2 on an iPad 4 with Safari.
Version: master
Severity: normal
OS: other
Platform: Tablet PC
Upstream issue: https://github.com/ajaxorg/ace/issues/37
Looks like the branch for iOS support hasn't gotten kept up to date; so somebody'll need to give it some love.
As a workaround, tap on the "/*" button on the toolbar to disable the syntax highlighting editor and go back to a plain <textarea>. Not pretty, but you can edit.