trickle is a portable lightweight userspace bandwidth shaper. It
can run in collaborative mode (together with trickled) or in stand
alone mode.  trickle works by taking advantage of the unix loader
preloading. Essentially it provides, to the application, a new
version of the functionality that is required to send and receive
data through sockets. It then limits traffic based on delaying the
sending and receiving of data over a socket. Trickle runs entirely
in userspace and does not require root privileges.