JDBC Pools

HikariCP is a "zero-overhead" production ready JDBC connection pool.

Commons Database Connection Pooling

Apache Commons DBCP software implements Database Connection Pooling

a JDBC Connection pooling / Statement caching library

c3p0 is an easy-to-use library for augmenting traditional (DriverManager-based) JDBC drivers with JNDI-bindable DataSources, including DataSources that implement Connection and Statement Pooling, as described by the jdbc3 spec and jdbc2 std extension.

Tomcat JDBC Pool Package

Lightweight connection pool.

Ultimate JDBC Connection Pool

Open Source XA JDBC Pool

Concurrent, fast, and fully-featured JDBC connection pool, which provides a non-starvation guarantee for application threads, slow SQL queries detection and logging, and Hibernate integration, among other features.