A modern Web application looks significantly different from a decade ago. According to HTTP Archive,6 an average Web application is now composed of more than 90 resources, which are fetched from more than 15 distinct hosts, totaling more than 1,300 KB of (compressed) transferred data. As a result, a large fraction of HTTP data flows consist of small (less than 15 KB), bursty data transfers over dozens of distinct TCP connections. Therein lies the problem. TCP is optimized for long-lived connections and bulk data transfers. Network RTT (round-trip time) is the limiting factor in throughput of new TCP connections (a result of TCP congestion control), and consequently, latency is also the performance bottleneck for most Web applications.