blog API's

There are several API-s to retrieve, add, delete, ... data from / to / on blog servers.

An overview:
http://www.xml.com/pub/a/2003/10/15/dive.html

LiveJournal API:
http://livejournal.com/doc/server/ljp.csp.flat.protocol.html

Blogger API:
http://www.blogger.com/developers/api/1_docs/

MetaWeblogAPI:
http://www.xmlrpc.com/metaWeblogApi

Atom API:
http://code.blogger.com/archives/atom-docs.html
http://bitworking.org/projects/atom/draft-gregorio-09.html