There are a lot of freeware HTML editors, but most of them are just syntax highlighting editors of HTML source, with typing help, ie. providing shortcuts and helpers to insert HTML tags.
It is fine, I code most of my HTML by hand actually, but for new users (or pragmatic ones), it is better to have a visual editor, WhatYouSeeIsWhatYouGet (WYSIWYG), where you just drag an image where you want it, and so on.
I like to have control and I don't like much the code I see generated, but hey, they can even be useful to break down quickly a general layout, before tweaking it by hand.
Beside the ancesters, the awful FrontPage (awful for the generated code) and Netscape Communicator, I see a growing number of such free editors.
Of course, there are powerful and expensive professional tools like Macromedia (now Adobe) Dreamweaver, Adobe GoLive, and so on.
I list the freewares here as I find them. Already got 4 of them. Except for Nvu which I briefly tested, I didn't downloaded them so I cannot guarantee anything about them!
Nvu - I believe it uses Mozilla codebase (XUL), thus it is cross-platform (Windows, Linux, Mac OS, etc.).
Dynamic HTML Editor - The old version (1.9) is free, the new one (3.x) is shareware.
WYSIWYG Web Builder - The 2.x version (in the Download section) seems to be free.
<blink> - It was payware, it is now free. Mmm, the description lets think that it is WYSIWYG, but from the screenshots, it looks more like an HTML editor. A capable one, thought.