I would prefer xmlrpc.client over xmlrpc.tools and http.client over http.tools. The documentation and comments for these modules refer to them as client libraries. They do have some bits that could be used as tools, but I would guess that the vast majority of uses are as clients. The examples and test suites in these modules also only deals with the client use case, they don't test or demonstrate the tools portion of the code. -1 on http.xmlrpc.client. Yes, XML-RPC uses HTTP as a transport, but then HTTP uses TCP/IP as a transport, which would suggest socket.http.xmlrpc or tcpip.http.xmlrpc. HTTP is an implementation detail of XML-RPC. I've trained a number of bioinformaticians to use XML-RPC and for better or worse they are usually oblivious to HTTP. They can usually solve their XML-RPC needs with the abstraction of "XML-RPC communicates over the network to talk to remote servers" without needing to know any specifics about HTTP. http://docs.python.org/lib/module-xmlrpclib.html "XML-RPC client access" xmlrpclib.py: # # $Id: xmlrpclib.py 38463 2005-02-11 18:00:16Z fdrake $ # # an XML-RPC client interface for Python. # # the marshalling and response parser code can also be used to # implement XML-RPC servers. # http://docs.python.org/lib/module-httplib.html "HTTP protocol client" httplib.py: """HTTP/1.1 client library