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Onno Kluyt on Java at 20

I knocked on quite a few doors last month, looking for Java mavens to talk with about the language on its 20th birthday. Lots of people got back to me (I think they got tired of the banging), and I heard some great stories. But I was surprised that, to my first question -- "What has been the most significant change in the Java language and/or platform in the past 20 years?" -- no one answered, "Open sourcing Java." It's probably the way I phrased the question, but I remember Java jocks clamoring back in the day for Sun to release their beloved language under an open source license.

Onno Kluyt, who chaired the Java Community Process (JCP) from 2002 until he stepped down in July 2006, helped build the OpenJDK community and, as he puts it, "held the JCP together while we were doing the open sourcing and building that other community." I asked him the question I should have asked: "How important was the open sourcing of Java?"

"Looking back on it, it was too little too late," Kluyt told me via e-mail. "Linux was already very well established, and Android had happened. If Sun had open sourced Java two or three years earlier, some of the history might have played out differently. But the Microsoft lawsuits made that timing impossible."

You might remember that Sun sued Microsoft for $35 million in 1997, claiming that Microsoft breached its contract by trying to extend Java so it would work differently, and, MSFT argued, perform better, on Windows computers. They didn't settle until 2003. Three years later, Sun released quite a bit of Java under the GNU General Public License (GPL), and a year after that, finished the job.

You might also remember that Kluyt took some heat in 2003 for asking the community, "What do you think [the open sourcing of Java] does that people can't do today?"

"There were a lot of misconceptions about what Sun's license for Java before the open sourcing (SCSL) allowed or didn't allowed you to do," Kluyt explained. "It was a lot of more open and lenient than most developers were aware of. And so I asked that question a few times during developer events to get a discussion going about what developers felt they needed to do with the code base, what they wanted to do, and of those things what they believed they couldn't do now. To some extent Sun's open sourcing of Java was a symbolic act. It didn't really mean a change of heart about code contributions from the outside [or] a loosening of its grip on the core APIs. Put the code base under a well-known free and open source license and move on."

So, what was the most significant change?

"Over this time span that is a little difficult to answer," Kluyt said. "I would probably pick the HotSpot VM technology and the concurrency APIs, which together gave Java near-native performance and enabled large-scale, real-world deployments. But there are so many others: generics, closures, the added byte code making it much easier for other programming languages (Scala for example) to run on top of the JVM, servlets, JSPs.

What it is about the JCP that has allowed it to continue supporting Java in all its forms?

"Internally we often paraphrased Churchill: it's the worst kind of governance except for all the alternatives," he said. "Java has one inventor and one owner: first Sun and now Oracle. But it has interest from companies large and small beyond that one actor. And there were and are many great opinions and expertise outside Sun/Oracle on how to evolve it. In the JCP, Sun found a tolerable way to allow that outside influence, while keeping its seat at the head of the table. Sun could not, and now Oracle cannot, push through Java changes without some decent support from its competitors, and conversely, those competitors cannot push through significant change without some buy-in from Oracle. So both sides need each other. It came close to blowing up about two or three times but in the end: see Churchill's quote."

What is it about Java, the language, that has allowed it to evolve and thrive all these years?

"One half is the language; the other half is the platform, the virtual machine," he said. "Java was the first well-adopted language that had security and networking built in, that had a memory management model that shielded developers. Its syntax was easy to learn for C/C++ developers, its OOP concepts were easier to grasp than Smalltalk, and it made supporting multiple platforms significantly better than anything else around. Sun was also luckily with the adoption of Java in that its timing was great; the World Wide Web was just emerging and Java's characteristics happened to lend itself very well for that."

How important was the development of the Java platform?

"Maybe I'll answer it this way," he said. "No Java, no Android."

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Posted by John K. Waters on June 9, 2015