BlogEdit is an AIR-based (and therefore available on Windows, Linux, and theoretically Mac) application for simple blogging with MetaWeblog based blogs. It can create a new post, retrieve an existing post, or edit an existing post. It supports categories and manual html entering, and not a whole lot else.
If you like this software, feel free to enhance and distribute it, provided you comply with the 3-clause license of the xmlrpc library and 2-clause license of the main application.
If you have major issues with the software, there is no bugzilla or such up, so you must email the author at: firstname.lastname@example.org