You mean using WYSIWYG mode for template/theme editing? Yes, but honestly it depends on the forum - some insert alot of metachars so a simple plain old text editor like BBEDIT does the job nicely, too. In terms of adjusting the code layer of any software, RapidWeaver excels in my opinion and it's why it is suggested by a lot of users on this forum. It's not the only solution for that, everyone has their own likes and methods, but it certainly is popular for such applications. If you meant something else, need more specificity, please.
-jim