If you are tired of searching, downloading and testing lots of blog editor for Win or Mac / Linux, stop all those craps now. Try Google docs editor to create a post and publish to your blog account. Google docs by default supports Wordpress, Blogger, MoveableType blogs and the API based blogs.
Once you are done writing your content, Click on "Share" ( on top right hand ) -> "Publish as web page". You see the page ( Fig 1)
Fig 1. Publish this document
Fig 2. Configure your blog
Fig 3. Test the connection
Once you test the connection, click OK and then Publish your content. Done. You will see the content published into the blog. But the disadvantages are , you will not be able to attach a category and the tags to your post.