BoneCP is a Java JDBC connection pool implementation that is tuned for high performance by minimizing lock contention to give greater throughput for your applications. It currently beats all known connection pools, including C3P0 and DBCP, as shown on the benchmark section on the site.
Vibur DBCP is a new, concurrent JDBC connection pool based on Java dynamic proxies. It is fast, has concise source code, and supports a fairness parameter, statement caching, SQL query logging, and many other features. Various configuration examples (with Spring, Hibernate, etc.) are provided.