In this paper, we introduce JWire, a new component model for Java. JWire is designed for building dynamic architectures of components that use an open set of binding and communication protocols, and supports the use of architectural styles in assembling components. Using JWire, a system is composed of "wireable" components that each encapsulate state and behavior behind an interface defined as a set of named, typed roles. Components are wired together by creating bindings between compatible roles. Dynamic change is supported by meta-level descriptor objects that provide a common control interface to the binding protocols used to compose components.