"RPyC 3.0+, in a nutshell, has two modes to it: a "classic
mode," which was already available prior to its version 3, and a
"services mode," which was introduced in version 3. The classic
mode lacks any real security framework (which isn't always a bad
thing) and simply presents remote machines as if they were local
resources. The newer, services, mode isolates a collection of
published interfaces that a server supports and is secure inasmuch
as it prohibits everything not explicitly permitted. The classic
mode is essentially identical to Pyro (without Pyro's optional
security framework); the service mode is essentially RPC (for
example, XML_RPC), modulo some details on calling conventions and
implementation."