Sun sent the letter on Thursday afternoon, only a few days before Eclipse is set to break from founder IBM as an independent open-source project. Sun also reiterated its previous decision not to join Eclipse because that would mean abandoning its NetBeans open-source Java tools initiative, which forms the basis for Sun's commercial products.
Eclipse maintains a Java development tool platform -- also known as Eclipse -- that allows developers to mix and match different types of tools in a single programming application. NetBeans serves largely the same function, but has not garnered as much industry support as Eclipse. Before such software became prevalent, it was difficult, if not impossible, for many Java tools to work together.
The planned split from IBM is an important milestone for the open-source project, which has gained about 50 corporate members and broad support from Java programmers since it was founded in late 2001. With the project becoming an independent body, IBM's influence over the development of Eclipse technology -- and the Java industry overall -- could wane as other software companies join IBM on a new board of directors.
On Thursday, Sun warned that despite the change of status, a number of issues could still concentrate power in IBM's hands or serve to advance the business interests of some companies, rather than the Java industry -- Sun included -- as a whole. IBM has heavily invested in Eclipse software, which it's using across its entire software product line.
Although staunch rivals, Java software companies such as IBM, Sun and Oracle have also cooperated to ensure that Java software and tools can work together. The ability to share Java products and applications from different companies, which run on different operating systems, is an important selling point against Microsoft's Windows-centric software.
"The big-picture [goal] is a Java technology solution that ensures no 'lock in' to a given platform," the letter states. "We need to work together to make the Java platform a better, broader base for tools. That is the real issue."
In particular, Sun warned that the new bylaws of Eclipse give the position of executive director, now held by an IBM employee, an "unusual amount of power" to dictate the work of the open-source group. Sun also questioned whether IBM employees will continue to make up the majority of project staffers.
Finally, Sun urged Eclipse to explore and accept intellectual property from outside the membership of the open source group.
"Can [Eclipse] toe the very difficult line of being sensitive to the business interests of the participating vendors, and not just look at technology for technology's sake?" Sun asked in the letter.
Collaboration in the cards?
Eclipse representatives were not immediately available for comment. On Monday, Eclipse chair Skip McGaughey, also an IBM executive, said the organisation has maintained ongoing negotiations with Sun regarding membership. Eclipse members have also had conversations exploring ways to collaborate with the Java Tools Community, a group formed with participation from Sun to encourage interoperability among competing Java tools.
McGaughey said that membership in Eclipse does not mean Sun has to drop its commitment to NetBeans and that Eclipse and NetBeans could collaborate on technical matters. "We would treat Sun like any other company," said McGaughey.
Sun's open letter also addressed a number of technology differences that have separated NetBeans software from the Eclipse software. Overall, Sun said that business issues, rather than technical ones, have created the most conflict between the two groups.
IBM and Eclipse back a design that diverges from the official Java standard and that allows developers to create graphical user interface software that taps into the presentation capabilities of different operating systems. Sun's approach creates a common look and feel regardless of the underlying operating system.
But Sun said that it is already working to find a system of interoperability that would avoid incompatibilities between different Java applications. Eclipse, too, has a project exploring a system that bridges both approaches.
In the letter, Sun also took a clear stand on the issue of plug-ins, or add-ons, to Java tools.
The question is significant because Sun and other tools vendors want to ensure that a system for creating tool plug-ins can coexist with the Eclipse approach, which IBM favours. Large Java companies and Microsoft encourage add-ons to their products to make their tools more attractive to developers.
The Eclipse software creates a single "framework" that different types of programming tools can plug into, giving developers a single application to mix and match tools from different providers. Sun's NetBeans software and products from other Java software companies, such as Borland and BEA Systems, provide a similar but incompatible system for building add-ons to their respective products.
Creating a single plug-in framework for the entire industry "is a nonstarter when you think about the players involved," Sun said.
To help drive that interoperability, Sun called on Eclipse to join the official Java standardisation forum, called the Java Community Process, as well as the Java Tools Community.
"Don't define 'interoperability' on your own terms, but rather work with other major players in the industry to achieve actual interoperability," the Sun letter told Eclipse members. "Push the organisation to be a unifying force for Java technology."
