There has been a lot of buzz recently about "Web Services". A short examination shows that essentially a web services is an RPC (remote procedure call), generally across the internet, using SOAP/XML over HTTP.
RPCs are nothing new – so why all the excitement? Here are some reasons:
- Web services work over the internet, through firewalls. Getting other RPC technologied to do this can be challenging.
- Web services carry "WSDL" service descriptions, which will make it possible for software development tools to greatly automate the process of using them.
- Web services are truly language-neutral; many other technologies carry baggage that belies their origin in one primary language.
- Web services are text-based; the protocol is human readable and hence much more debuggable than (for example) IIOP, DCOM, RMI, etc.
Borland has made it near-trivial to expose functionality as a web service, or call web service functionity in Delphi 6. With just a few clicks the needed client or server side "stub" code is automatically generated, allowing you to use a web services as easily as any local function/procedure.
Many publicly accessible web services are listed at http://www.xmethods.net/