We describe work being performed in the Globus project to develop enabling protocols and services for distributed data-intensive science. These services include: * High-performance, secure data transfer protocols based on FTP, plus a range of libraries and tools that use these protocols * Replica catalog services supporting the creation and location of file replicas in distributed systems. These components leverage the substantial body of "Grid" services and protocols developed within the Globus project and by its collaborators, and are being used in a number of data-intensive application projects.