we present the first analysis of the join-the-shortest-queue (jsq) routing policy for web server farms. web server farms involve a collection of processor-sharing (ps) servers, whereas prior analyses of jsq have always assumed first-come-first-serve (fcfs) servers. this work introduces a new technique: single-queue-approximation (sqa), and uses the technique to prove some interesting insensitivity properties for web server farms. based on joint work with: varun gupta, karl sigman, and ward whitt.