The email, cited in court in California on Thursday by Oracle lawyer Annette Hurst, in response to suggestions that another company might use Java, read: ""Wish them luck. Java.lang.apis are copyrighted. and sun [sic] gets to say who they license the tck to," according to a report in Ars Technica.
Rubin's company, Android, which he set up in 2003, was bought by Google in 2005. He stayed on to head Google's project to develop a mobile operating system. There was a fair bit of pressure on him after Apple released the first iPhone in 2007.
Rubin was offered a lot of money if Android succeeded: he held stock worth US2.6 million at the time of acquisition and was offered US$8 million if the first phone was shipped within a certain time.
When five million phones were shipped, Rubin was due to get US$10 million, when 10 million were shipped he would earn US$15 million and when 50 million were shipped he would earn US$27 million.
Google began using features from Java in Android in 2007, the same year that it shipped its first phone. At that time, Java was owned by Sun. Oracle bought Sun in 2010 and sought to obtain licensing fees from Google. When the companies could not come to an agreement, Oracle went to court.
This particular email from Rubin is the only one — there were several emails cited in the earlier court case which ended in 2012 — where a Google employee gives an indication that he/she is aware that one cannot use APIs from Java without a licence.
The question being decided in this trial is how much damages, if any, Google needs to pay Oracle for the use of 37 APIs from Java in Android. The question of whether APIs are copyrightable has already been decided in the affirmative.
Rubin was also asked about another email, one that has been cited both in this trial and the earlier one in 2012. In this email, Google engineer Tim Lindholm wrote to Rubin that he had been asked by Google co-founders Larry Page and Sergey Brin about technical alternatives to Java.
Lindholm wrote: "We've been over a bunch of these, and we think they all suck. We conclude that we need to negotiate a license for java under the terms we need."
Rubin acknowledged that he remembered this email.