The document discusses how to write scalable network servers that can handle high loads with many concurrent connections. It begins by providing some background on the author and why high performance network code is important. It then shows simple examples of a basic HTTP client and server implementation. The document discusses issues with the traditional approach of using one process per connection, including the high latency of forking processes and scheduling overhead with many processes. It presents benchmark results demonstrating the performance costs of forking. The document advocates avoiding the one process per connection model for scalability.