Sun has released a new development kit aimed at mobile software developers.

The toolkit will allow developers to create user interfaces for Java-based mobile phone applications. The package is being made available for download by the company under the title 'Light-weight UI Toolkit' or LWUIT.

The company hopes that the open-source LWUIT will make it easier for Java developers to create applications for the Java ME mobile phone platform, further developing the growth of Java on mobile phones and smartphone handsets.

"By creating LWUIT, Sun is reaffirming its commitment to the mobile development community and by open sourcing the LWUIT code we are enabling mobile developers to quickly and easily create rich, portable interfaces for their applications," declared Craig Gering, Sun's senior director of embedded Java software.

"This software will also help address the mobile industry's fragmentation issue by enabling developers to create a single interface that will work anywhere Java is found."

The toolkit had previously been available to developers as a pre-release toolkit. The latest release, however, makes the kit available to developers under a variation of the GPLv2 licence.

The reasoning, said Sun senior technologist Terrence Barr, was to make it easier to commercialise products that use the LWUIT.

"To further accelerate the adoption of the LWUIT framework it is important to provide access to the source code under a liberal and well-known open source licence," Barr said in a blog posting.

"This licence choice provides the benefits of open source innovation and collaborative development while offering a risk-free path to adoption by commercial products – a model everybody should feel very comfortable with."