Andy Rubin, the head of the Google Android development team, took the witness stand for the first time yesterday in Oracle's lawsuit accusing Google of patent and copyright infringement in its Android OS.
Rubin tussled with noted trial lawyer David Boies, acting for Oracle in the case, over emails that Rubin sent or received in 2005 and 2006, when Google was first starting its Android development.
Oracle has accused Google of infringing its Java patents and copyrights in Android. Google denies any wrongdoing, saying it built a "clean room" version of Java that does not contain any of Oracle's protected intellectual property.
Oracle says the emails are evidence that Google knew it needed a licence for Java to build Android, but that it forged ahead without one because it failed to negotiate a Java licence with Sun. Oracle acquired the rights to Java when it bought Sun two years ago.
In one of the emails, Rubin wrote: "I think a clean room implementation is unlikely because of the team's prior knowledge, and it would be uncharacteristically aggressive of us to position ourselves against the industry."
"So you're saying that team had too much prior knowledge to operate in a clean room environment, correct, sir?" Boies asked Rubin.
"I think that's reading a lot into that small sentence," Rubin answered. "I wouldn't go that far."
In another email, Rubin wrote that the Java.lang API (application programming interface) was covered by copyright.
"You meant copyrighted by Sun, yes?" Boies asked.
"I didn't say that," replied Rubin.
"But you meant Sun, yes?" asked Boies.
Rubin: "Yes, in the context of this I think that I meant the APIs were copyrighted."
"By Sun?" Boies pressed.
"Yes," replied Rubin.
The Android chief was questioned for only 25 minutes, since he was called to the stand shortly before the trial ended for the day. Oracle will resume his questioning in the US this morning, when Eric Schmidt, Google's executive chairman, is also expected to testify.
Earlier yesterday, Oracle called Bob Lee, a former Google engineer who is now the CTO of mobile payments company Square, and John Mitchell, a computer science professor at Stanford University who Oracle hired as an expert witness in the case.
The trial is being held in three phases. This first, which could wrap up by the end of the week, is to determine the copyright accusations. The second is for the patent accusations, and the third will decide what damages Oracle will be awarded if it prevails on either of the first two.
That was the original plan anyway, although the judge in the case, William Alsup, indicated that he might ask the jury to decide any copyright damages at the end of this first phase. That's because any damages will depend partly on whether Google's copyright infringement was wilful, and the judge has said Rubin's emails might be evidence of wilful infringement.
He thinks it might be better, therefore, for the jurors to decide damages while the emails are fresh in their minds. He didn't make a decision on that yesterday but asked the lawyers for both sides to think about it.
A bigger question in the case is whether most of the code that Google is accused of copying can be protected by copyright at all. That's something the judge will rule on himself, based on the evidence in the case and his interpretation of the law.
The most serious copyright claim against Google involves 37 Java APIs, or application programming interfaces, that Google is said to have copied from Java for use in Android.
Google argues the APIs are a fundamental requirement for using the Java programming language, and that because the language is free for anyone to use without a licence, the APIs also cannot require a licence. Google also characterises the APIs as just "names" and "short phrases" that programmers use to invoke other parts of the platform.
Oracle disagrees. It argues that the "structure, sequence and organization" of the APIs took years for Sun's engineers to develop and are therefore subject to copyright. Mitchell, the expert witness for Oracle, backed up its claim.
"API design is a really creative process," he testified.
Mitchell said the Android APIs at issue in the case are "essentially identical" to those created by Sun. "I don't think there's any way a separate team could have come up with so many things that are identical except by copying the original APIs," Mitchell said.
On cross-examination, however, Google's lawyer got Mitchell to confirm that some of the Java APIs at issue in the case, such as java.io, are a requirement for the most basic functions in Java a program, such as networking to another computer.
Google's lawyer also got Mitchell to acknowledge that some of the APIs at issue are described in the book "The Java Language Specification," suggesting they're parts of the language and not something that need to be licensed separately from it.
Oracle may finish presenting its evidence in the copyright phase of the trial today, meaning Google will get to call its own witnesses and begin its defence.