In response to the exponential growth of Internet traffic, Web proxy caches are deployed everywhere. Nonetheless, their efficiency relies on a large number of intrinsically dynamic parameters, most of which can not be predicted statically. Furthermore, in order to react to changing execution conditions $such as network resources, user behavior or flash crowds, or to update the Web proxy with new protocols, services or even algorithms - the entire system must be dynamically adapted. Our response to this problem is a self-adapting Web proxy cache, C/SPAN, which applies administrative strategies to adapt itself and react to external events. Because it is completely flexible, even these adaptation policies can be dynamically adapted.