The primary goal of Novedit is to be a clone of notes taking editors like Keynote or WikidPad wich are only available on Windows. It is written in Ruby / Gtk and should run on Linux (mandatory), Mac and Windows.
Leo is:
An outlining editor for programmers. A general data management environment. A project manager and browser. Fully scriptable with Python. Written in 100% pure Python. Open Software
... [More], distributed under the Python License. Leo's home page is: http://webpages.charter.net/edreamleo/front.html
This (Google Code) project is dormant. For Leo's code, see https://launchpad.net/leo-editor/ [Less]