Microsoft's Internet Explorer version 5.5 and up supports a very useful feature called contenteditable. ContentEditable enables easy in-place editing of HTML by just setting an attribute or property.
At this moment Mozilla lacks this feature though there is a patch available from XopusEditor for v0.9x. There are plans to incorporate the patch in Mozilla version 1.1.
If I recall correctly, DotEdit uses ContentEditable.
-- MattWilkie - 04 Jun 2002
O' Reilly is keeping partial track for us...
http://www.oreillynet.com/pub/wlg/2449
... but they don't mention htmlArea...
http://www.interactivetools.com/products/htmlarea/
Note: In-browser editors tend to break on "enhanced" browsers despite the browsers using the IE MSHTML engine. (Netcaptor, for example).
-- LeeBottemiller - 26 Jan 2003