Didn't search Google did ya? A quick 5 second search with Google would have gave ya the answer...
Anyway, "wyswig" is an advanced HTML text editor. Not, an editor for HTML. It's a text editor, made from HTML. Well, it's made from HTML and some other programming languages and script languages.
I don't know what "wyswigpro" is, but just from looking at it, lol, it's a "pro" version or something of "wyswig".
I had already known what it was, I was just saying that Google helps alot.