Sequoia is a database cluster middleware that allows any Java™ application (standalone application, servlet or EJB™ container, ...) to transparently access a cluster of databases through JDBC™. You do not have to modify client applications, application servers or database server software. You just have to ensure that all database accesses are performed through Sequoia.
Sequoia is a free, open source project that is the continuation of the C-JDBC project (http://c-jdbc.objectweb.org) hosted by the ObjectWeb Consortium (http://www.objectweb.org/). Sequoia is licensed under an Apache v2 license (http://www.apache.org/licenses/LICENSE-2.0.html) is licensed whereas C-JDBC is available under the GNU Lesser General Public License (http://www.gnu.org/copyleft/lesser.html) (LGPL).
Sequoia also provides driver for non-Java applications. These developments are hosted in the Carob project (http://carob.continuent.org). An Eclipse plug-in for Sequoia is also available in the Oak project (http://oak.continuent.org).