The present invention discloses a solution for developer customization of Web 2.0 applications based on relationships between a content creator and a content requester. In the solution, Web 2.0 content can be received from a content creator. One or more creator established customizations can also be received where the customizations are each a set of one or more users. In the method, a communication can be established with a user who requests the Web 2.0 content. It can be determined that the user is a member of a set specified by the content creator. The customization associated with the set can be applied. Web 2.0 content as modified by the customization can be served to the user. In one embodiment, users can also establish customizations, which are also applied to the served Web 2.0 content.