We give a short introduction to Asynchronous Constraint Solving (ACS), which is a new execution model to solve constraint satisfaction problems through constraint propagation and search. Propagation is based on the theory of chaotic iteration and search is implemented with explicit constraint retraction. ACS is designed for the object-oriented development of distributed or strongly interactive applications. Our implementation J.CP makes use of this new execution model. J.CP is a Java package, which combines the declarativity of constraint programming with the features of the object-oriented programming language Java. Constraints are autonomous objects that can be posted and retracted in concurrently running solvers that communicate via common constraint variables.