13. A non-transitory computer-readable medium comprising instructions for execution by a computer, the instructions including a computer-implemented method for providing a mashup, the instructions for implementing: providing a mashup that performs an action on a resource included in the mashup; identifying an attribute of a user running the mashup to perform the action on the resource; and providing an access control, the mashup being associated to a permission artifact, the permission artifact specifying a principal and whether one of to permit and to prohibit the principal to take the action on the resource, wherein the access control is triggered only when the mashup attempts to perform the action on the resource, the access control (i) checks whether the attribute of the user running the mashup to perform the action is predefined as belonging to the principal specified in the permission artifact associated to the mashup, and then (ii) performs the one of to permit and to prohibit the action on the resource only when the attribute belongs to the principal, plural users that have a same single attribute belong to the principal when the same single attribute is defined as belonging to the principal, and the permission artifact further specifies: (i) the resource used by the mashup, and (ii) the action on the resource for which permission is needed.
16. The computer-readable medium of claim 13 , further comprising specifying, via a user interface, in the permission artifact, the principal, the action, the resource, and that the principal is one of permitted and prohibited from taking the action on the resource.