Sun has released Netbeans 5.5, the latest version of the company's open-source Java IDE. The company's aim is to beef up the software's productivity tools and improve its look-and-feel.

The company estimates that there have been more than 11 million downloads of NetBeans since its debut as open-source technology in June 2000. NetBeans competes against the open-source Eclipse Foundation's Eclipse IDE in providing developers with the tools to build cross-platform desktop, enterprise, web and mobile applications.

New features in NetBeans 5.5 include Java Persistence API and Java API for XML Web Services (JAX-WS) 2.0 productivity tools, and support for the open-source version-control system Subversion. Also in the new release of NetBeans are enhancements to its GUI builder, work previously carried out under the code name of Project Matisse.

Sun also released five value-added packs for NetBeans 5.5, including a technology preview of NetBeans Visual Web Pack for developing applications using JavaServer Faces (JSF) as well as a beta version of NetBeans C/C++ Pack, which enables C or C++ developers to use NetBeans alongside their own compiler and tools. The NetBeans Enterprise Pack brings together tools for creating and testing SOA applications.

The vendor additionally announced the expansion of its NetBeans strategic partner programme to feature increased technical support and more opportunities for members to co-market their software with Sun. Formally established in November of last year, the programme is aimed at companies that build NetBeans add-ons and evangelise the IDE to their developers. Members include CollabNet, the JBoss division of Red Hat and Sony Ericsson Mobile Communications.

NetBeans 5.5 runs on operating systems including Microsoft Corp.'s Windows, Linux, Apple Computer Inc.'s Mac OS X and Sun's own flavor of Unix, Solaris. The software supports Sun's Java Platform Enterprise Edition 5 (Java EE) as well as other versions of Java -- Java Platform Standard Edition (Java SE) and Java Platform Micro Edition (Java ME).

Sun is midway through a plan to make all its software freely available, including its core Java technology. Last week, Jonathan Schwartz, Sun's chief executive officer and president, committed to open-source Java within the next 30 to 60 days.