Oracle has filed suit against Google, alleging that Google infringes patents on the Java Programming Language that Oracle purchased with its acquisition of Sun Microsystems. Java is the language used to implement the popular Android mobile-phone platform.
The industry standard Java language is available for free use, due to a patent grant made by Sun Microsystems before its acquisition by Oracle. It is used by many companies without payment of any royalties.
The Java Language Specification includes this patent grant language:
Sun Microsystems, Inc. (SUN) hereby grants to you a fully paid, nonexclusive, nontransferable, perpetual, worldwide limited license (without the right to sublicense) under SUN's intellectual property rights that are essential to practice this specification. This license allows and is limited to the creation and distribution of clean room implementations of this specification that:
(i) include a complete implementation of the current version of this specification without subsetting or supersetting;
(ii) implement all the interfaces and functionality of the required packages of the Java 2 Platform, Standard Edition, as defined by SUN, without subsetting or supersetting;
(iii) do not add any additional packages, classes, or interfaces to the java.* or javax.* packages or their subpackages;
(iv) pass all test suites relating to the most recent published version of the specification of the Java 2 Platform, Standard Edition, that are available from SUN six (6) months prior to any beta release of the clean room implementation or upgrade thereto;
(v) do not derive from SUN source code or binary materials; and
(vi) do not include any SUN source code or binary materials without an appropriate and separate license from SUN.
Given that, it's not clear what Oracle is after. Could it be that Google's Java implementation does not meet the above requirements? The text of Oracle's claim is not yet available.