CloudVPN is a secure decentralized mesh networking tool. It allows applications to use it as a mesh transport layer for packet routing, easily creating mesh ethernet VPN, secured audio/video broadcasting or communication channels, etc. It can create secured networks with special or weird topologies, so it's very easy to create connection schemes with clustered/decentralized servers, topologies with better throughput, ring-like topologies for failover, long-line for passing through many routes, or tree topology for optimizing inter-server bandwidth needs.
sshh is a set of two daemons that allows you to maintain a TCP connection if all you have available is an HTTP proxy. It is similar in functionality to httptunnel, but has a few more features. Once you have it set up, sshh will allow you to make connections forward through the proxy or backwards through it, so you can open connections in either direction.
EARL is an HTTP tunneling proxy. It uses the POST method to transfer data. Since its datagrams are serialized objects, the traffic overhead is rather large. The datagrams are encrypted using AES to provide privacy and obfuscation to proxy maintainers. Inbound and outbound connections are possible. It is recommended to combine it with SOCKS proxies for a comfortable setup.