Java offers the basic infrastructure needed to integrate computers connected to the Internet into a seamless distributed computational resource: an infrastructure for running coarse-grained parallel applications on numerous, anonymous machines. First, we sketch such a resource's essential technical properties. Then, we present Javelin, an infrastructure for global computing. The system is based on Internet software that is interoperable, increasingly secure and ubiquitous: Java-enabled Web technology. Ease of participation is seen as a key property for such a resource to realize the vision of a multiprocessing environment comprising thousands of computers. Javelin's architecture and implementation require participants to have access to only a Java-enabled Web browser. The security constraints implied by this, the resulting architecture and the current implementation are presented. The Javelin architecture is intended to be a substrate on which various programming models may be implemented. Different computation servers, each corresponding to a different programming model, are supported by Javelin's architecture. Several are presented briefly. Experimental results are given in the form of micro-benchmarks, a Mersenne Prime application and a ray-tracing application that run on a heterogeneous network of several parallel machines, workstations and PCs. ยฉ1997