Sun Microsystems and the NetBeans open source group today introduced the NetBeans integrated development environment (IDE) release 4.0.

Sun modestly claimed that the latest NetBeans release marks a "monumental milestone" for the project as it is the first open source IDE to support the J2SE 5.0 language features. It is also the first IDE to base its project system entirely on Apache Ant.

NetBeans 4.0 is designed to offer modular Java technology development for Linux, Macintosh, Solaris and Windows platforms.

All key functionality is included with the initial download of the software, rather than via the addition of a series of plug-ins, Sun said.

NetBeans 4.0 includes Tiger J2SE 5.0 language support including constructs, such as enums (enumerated types), generics or metadata annotations to build and edit applications without additional set-up.

It also ships with a project system based entirely on Apache Ant, and refactoring features designed to provide simplified code maintenance for developers.

Web application development improvements include extended support for J2EE version 1.3 and 1.4 platform standards.

NetBeans 4.0 also boasts expanded support for J2ME, including Mobile Information Device Profile 2.0, and Connected Limited Device Configuration 1.1, and tight integration with the J2ME Wireless Toolkit 2.2.

"The arrival of the NetBeans 4.0 IDE now puts in the hands of developers the full range of Java technology development with a robust open source IDE straight out of the box," said Jeff Jackson, Sun vice president of Java developer platform and strategy.

"Sun and the NetBeans community will continue to provide cutting edge technology for Java developers to create innovative applications."

For a full list of features or to download the NetBeans 4.0 IDE visit www.netbeans.org.

The next release, NetBeans 4.1 IDE, will be available next year and will deliver improved development capabilities for J2EE applications including support for Enterprise JavaBean components and web services for the first time.

The Early Access version of release 4.1 is now available and has over 15 new modules for developing J2EE 1.4 technology-based applications. It can be downloaded here.