Differences between FCKeditor and CKeditor?

Question

Sorry, but I've not been able to locate anything (even on the official pages) informing me of the differences between the two versions.

Even a query on their official forum has been unanswered for many months -

The license page talks a bit about the "internal" differences

CKEditor Commercial License - CKSource Closed Distribution License - CDL

...
This license offers a very flexible way to integrate CKEditor in your commercial
application. These are the main advantages it offers over an Open Source license:

* Modifications and enhancements doesn't need to be released under an Open Source
  license;
* There is no need to distribute any Open Source license terms alongside with your
  product and no reference to it have to be done;
* No references to CKEditor have to be done in any file distributed with your 
  product;
* The source code of CKEditor doesn’t have to be distributed alongside with your
  product;
* You can remove any file from CKEditor when integrating it with your product.

Answer 1

Because FCKeditor can be read as F*ckeditor, they decided to change the name to CKeditor (FCK stands for the name of the author of it, Frederico Knabben)

Development goes further with the name "CKEditor", "FCKeditor" is kept for legacy purposes. New applications should use CKEditor, it's much faster and the interface looks pretty well.

A final note: FCKeditor contained a built-in file uploader/browser. This feature has been removed from CKEditor, and separated to CKFinder. Unfortunately, CKFinder is not free and without paying for it, you can only use it in "demo mode". Its features will be fully available, but an ugly notice will be displayed and the application may not be used for real world applications:

5. Unlicensed Copies

If you did not pay for a license, you may use unlicensed copies of CKFinder for the exclusive purpose of demonstration. In this case you will be using CKFinder in "demo mode". Without derogating from the forgoing, you may not use CKFinder in "demo mode" for commercial purposes. CKFinder shall be used only for evaluation purposes and may not be used or disclosed for any other purposes, including without limitation, external distribution or software development. You may not remove demo notices from the interface nor disable the ability to display such notices or otherwise modify CKFinder. Product support is not offered for CKFinder in "demo mode".