Blogging API's in PHP

We need a function/class in PHP that will post content to various blogging platforms or CMS’s. Basically we want the functionality of Microsoft LiveWriter or the Mozilla ScribeFire plugin but WITHOUT the user interface. We want to be able to programmatically post and edit posts with text and pictures to one of multiple sites that uses one of multiple CMS’s. We also need the ability to schedule posts to be published at a later date. The different API’s should be abstracted so that we do not need to deal with the details of each one. The development process will be staged – first we want to see working connections to Wordpress (both Wordpress and independently hosted) and Blogger API’s and then we will move on to 5-10 other platforms. Interested developers please respond with: Recommendations, description of the expected stages of their development process.