The EMBL Data Library was established in 1980 to collect, organize and distribute published nucleic acid sequence data. At that time GenBank was being established in America with an almost identical brief. The two groups decided to collaborate, and this collaboration still fluorishes today. Twelve releases of the Nucleotide sequence Data Library have now been distributed, and the collection has grown from half a million to about 14 million bases (Release 12, July 1987). The data are distributed to about 200 sites in 25 countries, and many software developers redistribute them with analysis software. In all, the nucleotide sequence collection is in use by some 10000 scientists throughout the world. The Data Library Group within EMBL has 8 full time staff, and is funded entirely within the budget of the Laboratory.