MarsEdit

MarsEdit is a weblog editor for Mac OS X. It supports posting to many popular blogging services, such as Blogger, Movable Type, Tumblr and WordPress.
History.
MarsEdit was originally developed as a component of NetNewsWire, a popular news aggregator for Mac OS X, which, in the 1.0 series, included a simple weblog editor. During the development of NetNewsWire 2.0, the developers decided to move the blog editor functionality to a new application. The resulting application, MarsEdit 1.0, was released on November 28, 2005.
With the acquisition of NetNewsWire by NewsGator in 2005, the future of MarsEdit was uncertain for a time. On November 4 of 2005, it was revealed that MarsEdit development would be continued by Gus Mueller of Flying Meat.
In February 2007, MarsEdit was purchased by Red Sweater Software, and is now being developed by Red Sweater's owner, Daniel Jalkut.
MarsEdit 2.0 was released in September 2007, with a refined user interface and several new features including Flickr integration.
MarsEdit 2.3 was released in March 2009 and includes support for the popular Tumblr blog service.
Marsedit 3.0 was released in May 2010 and includes WYSIWYG editing, enhanced WordPress support, and image library integration.