CKEditor 4 plus MODX Evolution (CMS system)? Yes/No?

Anyone here using the (open source content management system) MODX, using the "Evolution" (not "Revolution") version?

How do I get CKEditor installed as a MODX plug-in? Do I get an archived copy of CKEditor 3, install the MODX plug-in, then upgrade the CKEditor to 4.x?

Any ideas?