Weber carburettors were originally produced in Italy by Edoardo Weber as part of a conversion kit for 1920s Fiats. Weber pioneered the use of twin barrel carburettors with two barrels (or venturi) of different sizes, the smaller one for low speed running and the larger one optimised for high speed use.
In the 1930s Weber began producing twin barrel carburettors for motor racing where two barrels of the same size were used. These were arranged so that each cylinder of the engine has it's own carburettor barrel. These carburettors found use in Maserati and Alfa Romeo racing cars.
In time, Weber carburettors were fitted to standard production cars and factory racing applications on automotive marques such as Abarth, Alfa Romeo, Aston Martin, BMW, Ferrari, Fiat, Ford, Lamborghini, Lancia, Lotus, Maserati, and Porsche.
In modern times, fuel injection has replaced carburettors in both production cars and motor racing. Weber fuel system components are distributed by Magneti-Marelli After Market Products and Services.

In 2004 Weber carburettors went out of business owing partly to the fact of the modern world of fuel injection and mass production engines.
This lead to a number of companies producing replicates of the carburettor, such as EMPI with the HPMX range and Dellorto (http://www.dellorto.co.uk/).

There is still a wealth on information available on the Weber carburettors, this can mainly be found at http://www.redlineweber.com/

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