I have been running the wysiwyg editor; tinyMCE on a couple of sites and have now succesfully installed within a copy of ExpressionEngine 1.3.
In fact it doesn't seem any different from my experience with 1.2. It seems like a few people might find it useful to get some advice as to how to set tinyMCE up. One point before we begin though; tinyMCE does not work with Safari on MAC (up to version 2 anyway) and does not work with Opera as far as I can tell. The best browser on any platform is FireFox and it works with this and Mozilla / Netscape. Internet Explorer is also fine although you will need to take care when copying and pasting content from Word. Here, then are the steps to get tinyMCE working: