It should be possible to detect CKEditor version on the server side

[Wiktor Walc]

Based on ​http://ckeditor.com/forums/CKEditor/Provide-Details-about-CKEditor-in-machine-readable-form

Relying on parsing minified JavaScript code of ckeditor.js with regular expression to get CKEditor version number has a risk of stopping working at any moment, due to code refactoring, improved minification method etc.

Although the version number of CKEditor doesn't say a lot about the CKEditor itself anyway (various custom builds exist etc.), it still can say something regarding e.g. available configuration options, that can be later displayed in the administration backend.

Separate file?

By adding a separate file with information about CKEditor build, we'd start confusing users with too many irrelevant files in the main folder.

build-config.js?

Including version number and revision in this file would be confusing again, as it may suggest that uoploading it to the online builder would result in building the same version again (e.g. 4.3.2 while 4.4.3 already exists).

ckeditor.js

My suggestion is to use the very first comment at the top of ckeditor.js (with copyrights), where such information could be added by both command line and online builder:

/*
Copyright (c) 2003-2014, CKSource - Frederico Knabben. All rights reserved.
For licensing, see LICENSE.html or http://ckeditor.com/license
Ver:4.4.2 Rev:1567b48
*/

[Piotrek Koszuliński]

I agree with the downsides of using build-config.js for that. The ckeditor.js file seems to be most suitable. Separate file (package.json?) would make sense, but since we've got nearly unlimited number of possible builds and 3rd party plugins, we would have problems with project name, site, bug tracker, etc, so maybe better not use it.