1st Page 2000 for Windows. Download it from
http://www.evrsoft.com
For Linux, my PCQ Linux 2005 has one good tool already installed in Developer's section. I think it is a pretty common tool. I will let you know the name as soon as I get back to that machine.
Both these tools that I am talking about are *NOT* WYSIWYG editors. So if you want WYSIWYG editors, take what swatkat has recommended.