A system and method are disclosed for decreasing the number of duplicate library copies loaded into memory without endangering the security of applications in a runtime environment. In a preferred embodiment, applications in the runtime environment may be provided with a delegation classloader that identifies any libraries referenced by the delegation classloader's respective application. The delegation classloaders then delegate the task of providing the referenced libraries to a distinct software component. In a preferred embodiment, the distinct software component may be another delegation classloader or other loader adapted to look at a single library or a small set of libraries. These "atomic" classloaders can be freely shared by multiple applications since they do not expose any application's internals. Each atomic classloader preferably loads one copy of its associated library or libraries into memory. This single instance of shared library code is made available to multiple applications without requiring explicit cooperation between applications or endangering their security.