Have you looked at Fidus Writer? It's an open source collaborative WYSIWYG LaTeX editor. With the documents that I used to test it, I didn't notice any slowdown

Have you looked at Fidus Writer? It's an open source collaborative WYSIWYG LaTeX editor. With the documents that I used to test it, I didn't notice any slowdowns. http://fiduswriter.org/ http://fiduswriter.org/