msg-rpc provides bidirectional RPC support over a simple message interface such as WebSocket. Tere are WebSocket examples based on socket.io and sockjs. It just has a simple sendMessage/onMessage interface, with no other dependencies. It supports not only normal RPC, but also RPC Service, which makes RPC pushable (i.e. the server can also send a request to the client and expect some kind of response).
Collax Business Server is an all-in-one Linux server for small- and medium-sized businesses. It delivers all the important network services within a heterogeneous business environment for communication, infrastructure, compliance, groupware, and storage, all in a reliable and secure way which is easy to manage. It also provides essential security functions such as firewalling and virus and spam filtering, to protect against hacker attacks, viruses, and unsolicited email messages.