A client recently asked if I could install FCKeditor into Movable Type. Thanks to some detailed instructions, it was surprisingly easy.
In a nutshell, declare the FCKeditor Javascript, then later on you need to load the instance of the editor. The instructions above actually point to loading it during the onload event, so that all three default MT text areas (entry body, extended entry and the entry excerpt) are running FCKeditor when you pull up the page.
This is a bit slower, and perhaps overkill, so we found some other directions about loading the editor on demand. These are for a different CMS, but they will certainly work. I modified the instructions slightly and created a different load routine for each of the three text areas. Then I added a doubleclick event to each textarea which called the appropriate routine. So when you’re done, the editor simply starts up on a double-click in that text area.
The only problem I had during the process is that there was an illegal character in one of the configuration files. If you get an error about this, simply edit the character and replace it with an “F” (I think it was an “F” – it should be pretty obvious which character you need to replace).