trickle is a portable lightweight userspace bandwidth shaper.
It can run in collaborative mode 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.