Make sure to read the disclaimers about this page at FreeOpenServicesDefinition.

• The GPL restrictions on redistribution have the useful side-effect of minimizing the free-rider problem; the Affero GPL and OSL take this one step further by defining distribution to include web publication. Is there an appropriate non-source (API-level) analogue for these restrictions on redistribution? (i.e., 'you can only use this source if you agree to make the APIs available under non-restrictive TOSs?')