From kragen@dnaco.net Sun Aug 2 18:01:47 1998 Date: Sun, 2 Aug 1998 18:01:46 -0400 (EDT) From: Kragen To: clug-user@clug.org Subject: CORBA & XML-RPC Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Keywords: X-UID: 980 Status: O X-Status: Dave Winer is promoting something he calls XML-RPC as a substitute for CORBA. Basically, to invoke a procedure remotely, you connect to an HTTP server at the place where you want to invoke the procedure and send the procedure name and the contents of the procedure's arguments in an XML document in the body of an HTTP POST request. The return value for the procedure is returned as an XML document in the body of the HTTP reply. It has some disadvantages compared to CORBA. The primary disadvantage is that it's slower (by several orders of magnitude, I should think). It also doesn't address any of the other numerous issues CORBA does, like lifetime, persistence, etc. However, it has several advantages compared to CORBA: - the specification document for XML-RPC is only about five pages long; - it's easy to read and modify calls and returns without any spec or software tools (other than "cat"); - it won't have trouble crossing firewalls; - it's much easier to implement. Dave wants to put a little baby HTTP server in every app, so that you can easily invoke any procedure remotely, so you can use any scripting language you want with any app, and you can write a single script which controls several apps via RPC. His Frontier scripting environment already sports XML-RPC support. I think PARC also created an RPC-over-HTTP mechanism, called 'HTTP-NG'. I don't know much about it. Kragen