XML-RPC stands for XML Remote Procedure Call. In laymans term, it lets you send and receive data using a specific XML format.
You can access it at pinger.blogflux.com/rpc/
For those that need a breakdown, it is:
Most blog software (such as Movable Type or WordPress) lets you enter a URL (or URI) to ping. Put http://pinger.blogflux.com/rpc in that field. Now every time you add a new post, your blog software will automatically use our Pinger!
Our XML-RPC server supports both weblogUpdates.ping and weblogUpdates.extendedPing.
Even if your software already provides out of the box pinging support, it is usually to only one service. Our service pings 10 while making it very easy. See the actual pings go through in real time.
An odd question, but see our FAQ to allay any fears you may have.