I am currently in the progress of implementing the necessary features and components in my weblog software to allow the use of a standalone client to post entries (and ultimately edit, as well). As I'm already beta testing a bunch of other Live tools, I thought I'd start with Windows Live Writer.
The current beta version supports:
- Movable Type
- WordPress (inc. 2.2+)
- Community Server
- Radio Userland
Additionally, it supports two raw APIs on anything that implements them:
- Metaweblog API
- Movable Type API
Not bad. So, I've chosen the Movable Type API for mine, but I'm jumping ahead - there's something else, something really cool, that I should mention.
Really Simple Discovery, RSD, is a method by which a tool can identify information about a page and its supported editing schemes. Including a link in the main weblog page with rel="EditURI" to point to the RSD file (which is XML), and that indicates which editing APIs are supported and their respective URIs.
Windows Live Writer checks for and uses the RSD information, which results in a 3-entry configuration: weblog URL, username and password. It doesn't get much simpler than that.
Still to come: the Movable Type API, Blogger, categories and more.