1. Terminology and introduction

Programmers write programs; administrators configure these programs into systems; users apply these systems to their tasks. Some individuals combine these roles, but most do not. For instance, some expert users are also expert programmers but most are not; most users rely instead on the large available body of general-purpose programs written by others. Similarly, some expert users are also expert administrators but most are not. System administration can be difficult and painstaking work; programs in a system can interact in unexpected ways, and installing one program can Making system configuration more declarative very readily break another. Unfortunately, the users of personal systems must typically administer their own systems, and we believe that this creates barriers to the wider adoption of new personal systems. As a result, a great many personal systems are poorly configured and poorly maintained. They do not work well. They are undependable. They are brittle. They are insecure. How might we do better