ProxySQL is a high performance, high availability, protocol aware proxy for MySQL and forks (like Percona Server and MariaDB).
All the while getting the unlimited freedom that comes with a GPL license.
Its development is driven by the lack of open source proxies that provide high performance.
Official website: http://www.proxysql.com/
Benchmarks and old blog posts can be found at http://www.proxysql.blogspot.com/
Forum: https://groups.google.com/forum/#proxysql/