XML-RPC Spell Checker

"I was able to whip this up in VS.NET using XML-RPC.NET in short order, it really needs a spell checker widget though (hey, MSFT wake up!, there's a spell checker API bundled in OSX)" [Simon Fell]

Have you checked this out: http://www.stuffeddog.com/speller/doc/rpc.html
It's a spell checker with an XML-RPC front end.