AppleScript for guessing the text editor you currently use. It's intended to be used in Keyboard Maestro. Read more here: http://rocketink.net/2014/05/upload-to-gist.html.

guess-editor.scpt

set activeEditorsList to {}
set appList to {"nvALT", "FoldingText", "Byword", "Mou", "Sublime Text", "MultiMarkdown Composer"}

--    Generate variable with running apps
tell application "System Events"
	set activeProcesses to (name of every process)
end tell

--    Generate list of running text editors    
repeat with appName in appList
	if appName is in activeProcesses then
		set end of activeEditorsList to appName
	end if
end repeat
--return activeEditorsList

set editorCount to count activeEditorsList
if editorCount = 1 then
	return item 1 of activeEditorsList as text
else if editorCount > 1 then
	activate
	return choose from list activeEditorsList
else
	return "cancel"
end if