Source : Free On-Line Dictionary of Computing

Emitter Coupled Logic
     
        (ECL) (Or "Current Mode Logic") A technology for building
        logic gates where the emitter of a {transistor} is used as the
        output rather than its collector.  ECL has a propagation time
        of 0.5 - 2 ns (faster than {TTL}) and a power dissipation 3 -
        10 times higher than {TTL}.
     
        (1994-11-09)