In brief, xmlrpc is the method of remote procedure call, where call info is xml encoded.
xmlrpc server exposes a set of remote methods with input arguments and return type.
xmlrpc supports following argument types:
- int integer value
- double double-precision floating point value
- boolean boolean value
- string string value
- dateTime date/time value
- base64 base64 encoded binary data
- array array of values
- struct structure, where each member has name and value (similar to associative arrays)
Description of Wordpress methods exposed through xmlrpc
To add a post, you need to call wp.newPost with arguments: blog id, username, password and structure, representing post content.
XMLRPCPHP is a good choice.