easy to use but powerful traffic shaping tool (docs)

 FireQOS generates generic traffic shapers with an extremely simple but
 powerful configuration language based on bash, enabling you to design
 any kind of traffic shaping with ease.
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 FireQOS is the traffic shaper counterpart of the FireHOL firewall;
 both FireHOL and FireQOS support IPv4 and IPv6.
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 This package contains documentation and examples.