BSD Sockets has been a de facto standard API for network programming. While it provides a simple and portable way to perform network I/O, it shows suboptimal performance for “message-oriented” network workloads, where connections are short or messages are small. This problem is exacerbated by its poor scalability on multi-core processors. In this work, we explore the benefits of a clean-slate design of network APIs aimed at achieving both high performance and ease of programming. We present MegaPipe, a new API for efficient, scalable network I/O, and evaluate its efficiency and effectiveness with a proof-of-concept implementation.