The development of two promising Open Source browser-based WYSIWYG XML editors come to the next round:
Giuseppe Bonelli is looking for developers joining him to (re-)start development  of the Xopus  Open Source version. This is a WYSIWYG XML editor based on MS Internet Explorer.
I am awaiting a profound rewrite of Bitfluxeditor , a Mozilla-based WYSIWYG XML editor, which hopefully might happen in the foreseeable future. This rewrite is called BXE-NG (Bitfluxeditor Next Generation) and might be based on Mozile . See the threads in the BXE mailinglist for more infos. .