Table:
text: Comparison of JavaScript-based source code editors
Overview
List of source code editors
Editor Site Style_clone_of Cost_US_ Open_source Activity
Ace (editor) Home, demo Sublime Text / Microsoft Visual Studio Free Yes Yes
CodeMirror Home, demo plain textarea Free Yes Yes
Orion Home Eclipse SWT StyledText, regular textarea Free Yes Yes
Monaco Editor example Microsoft Visual Studio used only by Microsoft No Yes
Markitup Home, demo Markup editor, no syntax highlight Free Yes Some
LDT Home regular textarea Free Yes Some
Ymacs Home, demo Emacs Free Yes Some
CodePress Home Microsoft Visual Studio Free Yes No
CodeTextArea Home, demo Microsoft Visual Studio Free Yes No
EditArea Home, demo Microsoft Visual Studio Free Yes No

Question: How much does an open source cost that isn't compared to JavaScript-based source code editors?