Latest version always available at http://md-wysiwyg.sourceforge.net/. Project page http://sourceforge.net/projects/md-wysiwyg
Markdown tools is a place holder for a collection of scripts/add-ons for John Gruber's Markdown http://daringfireball.net/projects/markdown/. If you are not familar with Markdown check out http://daringfireball.net/projects/markdown/ and the intro syntax page http://daringfireball.net/projects/markdown/basics.
Markdown basically is a light weight syntax for text files that creates html and looks good as the source text. Other markup projects typically have more features but the source text tends to look "busy".
Currently all the tools on this page are Python based http://sourceforge.net/projects/python-markdown. http://markdown.infogami.com/ has links to other tools and implementations on Markdown.
A minimal basic web-based GUI editor for Markdown.
Demo version of markdown wysiwyg is here http://md-wysiwyg.sourceforge.net/cgi-bin/cgi_wysiwyg_test.py/
Markdown wysiwyg uses:
Download from http://sourceforge.net/project/showfiles.php?group_id=163219&package_id=184446 requires everything listed above bar widgEditor.
An external post-processor that can be ran on the output that Markdown creates (the output could be generated with the original Perl version, Python, PHP, etc.). http://md-wysiwyg.sourceforge.net/src/markdown_postprocess.py
An extension to python-markdown http://sourceforge.net/projects/python-markdown so that a title and table of contents can be generated at the same time markdown formatting is applied. See http://www.freewisdom.org/projects/python-markdown/extensions/markdown_with_toc.py