FF (Ferguson Formula) Developments Limited (FFD) was a British company founded by Major A.P.R. (Tony) Rolt to exploit the 4WD technology begun originally at Dixon-Rolt Developments in partnership with Freddie Dixon and, from 1950 at Harry Ferguson Research. Rolt became Technical Director at Harry Ferguson Research until 1971, when the company was closed down.
According to Ward's Auto World[1] the influence that FFD had on all wheel drive (AWD) development transcended its size.