[otrs] webservices for otrs

Hi, Would like to know whether webservices are available for OTRS.i have found site where in user has accessed rpc.pl and created ticket using perl and php. is this the only way to use webservices in otrs.i would like to use asp/asp.net for accessing webservices in otrs.is there anyl wsdl file available for this. Ravi Shankar