Businesses that love Java and are looking to move to open source may want to give Compiere a look. The system is a complete ERP and CRM suite that includes accounting, order entry, customer information tracking, as well internal applications such as human resources, sales force automation and even customer call management functions.

The creators of Compiere bill the system as a "100% pure Java" platform. At the core of the application is the Java 2 Enterprise Edition run time environment and Enterprise Java Beans. Applications run on various module servers, which include a JBoss server, Compiere Server Services (the core application, which manages transactions between clients and a database server).

Other server modules include an accounting, request, Web, and utility servers.

A pure PC-based Java client is available, as well as an HTML-based interface tool. While the back-end database relies on Oracle, the developers say they are in the midst of porting the system to open source platforms such as MySQL and PostgreSQL.

The Java and Enterprise Java Beans components of Compiere allow for endless customization and tweaking of the system for users' requirements, according to the code's developers.

Compiere is licensed under the GPL and downloads are available for free.

Compiere is also one of the more commercialized open source ERP/CRM offerings, as it relies on Oracle and many other commercial Java development environment tools such as Borland and Rational. The developers also offer certification and training courses (in Germany) as well as telephone support services.

Next: an open source accounting package that sings.