LittleProxy is a high-performance HTTP proxy written in Java atop Trustin Lee's Netty framework. It's a side-project of LittleShoot and the Brave New Software Project. While many may still think of "high-performance" and "Java" as a contradiction in terms, the JVM has made astonishing strides over the years. That combined with Netty's use of event-based IO means that LittleProxy outperforms mod_proxy in every test we've ever run, beating it by as much as 83% on some tests using Apache Benchmark. LittleProxy is still a young project, but it works well.
LittleProxy is open source and used the Apache 2 license. If you would like to use LittleProxy under another license, please contact us at littleproxy at littleshoot.org or inquire on the forum.