Google CEO Larry Page (left) and Oracle CEO Larry Ellison will testify against one another in the coming weeks.
NEW YORK (CNNMoney) -- A landmark court battle between Google and Oracle has begun -- and its result will shape the future of the Android ecosystem fueling most of the world's smartphones.
Silicon Valley's power players are always in the throes of nasty patent fights against each other, but this one is especially potent. Oracle claims that Google's Android violates two patents plus several copyrights that Oracle holds on its Java software, a ubiquitous programming language powering everything from phones to websites.
Although both Java and Android are open-source platforms -- neither Google (GOOG, Fortune 500) nor Oracle (ORCL, Fortune 500) generally charge for their use -- their licensing terms are complex and precise. When Java creator Sun Microsystems (acquired by Oracle in 2010) set Java loose as open-source software, it left significant limits in place around the mobile version.
Companies building on top of Java's mobile platform typically pay to license it. Google used an elaborate workaround and essentially built its own version of a key system to avoid those licensing fees and restrictions.
Oracle cried foul and hauled Google off to court -- a move some expected from the moment it agreed to buy Sun.
"During the integration meetings between Sun and Oracle where we were being grilled about the patent situation between Sun and Google, we could see the Oracle lawyer's eyes sparkle," James Gosling, one of Java's original architects, wrote on his blog the day the lawsuit was announced.
After 20 months of prep work and a blizzard of court documents, the trial between the two tech titans kicked off Monday in San Francisco.
Google insists its approach to building Android -- now the most popular smartphone platform in the world -- did not infringe either Java's rules or Oracle's patents, and it thinks Oracle's copyright claims are a sham. It called Oracle's arguments "a classic attempt to improperly assert copyright over an idea rather than expression."
But Oracle thinks it's got a smoking gun: An e-mail sent from Google engineer Tim Lindholm to Android chief Andy Rubin just days before Oracle filed its suit. Warned in advance by Oracle that it believed Google was infringing its patents, Google asked Lindholm to investigate its options.
He didn't like any of them.
"What we've actually been asked to do [by CEO Larry Page and co-founder Sergey Brin] is to investigate what technical alternatives exist to Java for Android and Chrome," Lindholm wrote. "We've been over a bunch of these, and think they all suck. We conclude that we need to negotiate a license for Java under the terms we need."
Google fought to keep that e-mail out of bounds, but lost.
If its lawsuit is successful, Oracle could force Google to pay it tens of millions of dollars in retroactive licensing fees and potentially hundreds of millions more in the future.
But this isn't simply a damages case. Oracle already makes plenty of money. Adding to its stash would be a nice perk, but it's not the main motive for its legal crusade.
Oracle is picking a fight with Google because it feels that Android is threatening the Java platform it got as part of its blockbuster $7.4 billion Sun purchase. Android may be an off-shoot of Java, but its interface and functionality is unique. Code written for Java is not inherently compatible with Android -- and as Android grows, its version of Java threatens to become the dominant one.
Oracle doesn't want to kill Android, but it wants to force Google to play by its rules and make Android compatible with the rest of Java.
That would be extremely difficult for Google and the Android community. Each of the nearly 500,000 Android apps out there would have to be rewritten or tweaked.
But for Oracle, it would be a coup. Developers would be able to write apps around Java's programming interfaces that would also run seamlessly on Android devices.
"That would transcend whatever Google ultimately could pay Oracle," says Florian Mueller, a private intellectual property analyst and consultant.
New technologies like HTML5 are already making Java less important on the Web. Oracle wants to make sure it doesn't lose the rapidly growing mobile market as well.
Whatever the outcome, don't expect a big decision any time soon.
With so much at stake, experts like Mueller think that this case will get stuck in the courts for years. The two sides -- neither known for backing away from a fight -- will most likely battle and appeal their way straight up to the Supreme Court. 
