How to implement TinyMCE
We upgraded the WYSIWYG for Article Manager several years ago and there was some instructions here: http://www.interactivetools.com/forum/forum-posts.php?Notice-Artman-2.16-patch-for-wysiwyg-IE8-UPDATED-78266
Probably the simplest solution, though, would be to find an older browser that supported the WYSIWYG and use that for accessing the legacy programs. There's a list of supported browsers here: http://www.interactivetools.com/docs/pagepublisher/wysiwyg_editor.html
Hope that helps!