Precise counting of CCPN software users is handicapped by the fact that we do not enforce individual user registration. We therefore have to estimate our user numbers in other ways.
FormatConverter, which serves to translate between existing NMR and structural data formats, is probably the most widely used CcpNmr program. As it is pure open source, there is no way of counting users. FormatConverter is available as a web server and as standalone software. It is used internally in the BioMagResBank for reading and disambiguating deposited data, and is used in the WeNMR for converting data between calculation steps.
Analysis is the main program in the CcpNmr suite. It is free for non-profit organisations, and downloading requires registration. On the other hand a single download and registration is valid for an entire department, and people may well choose not to upload patches.
NB Add detailed metrics here NB
As of April 2012 we can identify ca 400 users from registration and mailing list records,counting only unique, geographically locatable names, and excluding developers. The user hail from 143 different institutions, distributed with ~20% in the UK, ~50% in Europe, and ~25% in North America.