## Facts

- Sun created and licensed the Java programming language and related “Java Technology.”
- Sun and Microsoft entered a 1996 Technology License and Distribution Agreement allowing Microsoft to create derivative works and distribute products incorporating Java Technology, subject to compatibility requirements (including passing Sun’s Java Language Test Suite).
- Sun alleged Microsoft intentionally introduced incompatibilities, including unauthorized extensions to the `java.*` libraries, to tie developers’ Java applications to Microsoft’s virtual machine and Windows.
- Sun alleged Microsoft declined to implement Sun’s Java Native Interface and instead promoted alternative interfaces (e.g., RNI and J/Direct) that further reduced cross-platform portability.
- Sun asserted Microsoft distributed these incompatible products broadly and used licensing and marketing practices that misled developers into believing they were creating portable Java applications.
- In 1998, the district court entered a preliminary injunction largely based on Sun’s likelihood of success on copyright infringement claims, restricting distribution of non-compatible Java products.
- In 1999, the Ninth Circuit vacated and remanded the injunction, directing reconsideration, including whether unfair competition principles supported injunctive relief and whether the challenged conduct was likely to recur.
- On remand, Sun moved to reinstate the earlier injunction under California’s Unfair Competition Law (UCL), independent of any copyright-based presumption of irreparable harm.

## Issues

1. Whether Microsoft’s distribution of non-compatible Java implementations, combined with related licensing and developer-directed statements, likely constituted “unfair” business practices under California Business & Professions Code § 17200.
2. Whether Sun satisfied the requirements for preliminary injunctive relief under the UCL, including a sufficient showing of likely ongoing or future harm, balance of hardships, and public interest considerations.
3. What scope of injunctive terms was appropriate to address incompatibility-driven market effects and developer deception risks.

## Decision

- The court granted Sun’s motion in part and reinstated portions of the prior preliminary injunction, with modifications, on the basis of the California UCL.
- The court found Sun showed a likelihood of establishing that Microsoft’s conduct constituted unfair competition and threatened ongoing and future harm, including fragmentation of Java’s cross-platform standard.
- The court concluded injunctive relief was warranted because the conduct reflected a strategy likely to continue absent court intervention.
- The court tailored relief to restrict certain distribution, licensing, and marketing practices involving incompatible Java implementations, including requirements directed at compatibility (e.g., conformity with agreed compatibility mechanisms) and limits addressing developer confusion.

## Legal Principles

- California’s Unfair Competition Law prohibits “unfair” business practices; conduct may be unfair where, in aggregate, it threatens market-wide harm by distorting competition and misleading participants in a technology ecosystem.
- Preliminary injunctive relief under the UCL may be justified where the plaintiff shows a likelihood of ongoing or recurrent harm and where the balance of hardships and public interest favor prospective restraints.
- In assessing recurrence and irreparability, courts may consider harms that are difficult to remedy after the fact, including loss of standardization benefits, network effects, and damage to business reputation from widespread developer reliance on misleading or incompatible implementations.
- Injunctions should be tailored to address both the technical source of competitive harm (compatibility and interface behavior) and associated deceptive or misleading practices that increase developer confusion.

## Conclusion

The district court partially reinstated preliminary injunctive relief under California’s UCL, concluding that Microsoft’s alleged strategy of distributing incompatible Java implementations and related misleading practices likely caused ongoing and future harm to Java’s cross-platform standard and to competition, and that a modified injunction was warranted to prevent recurrence and limit market distortion.


Sun Microsystems, Inc. v. Microsoft Corp., 87 F. Supp. 2d 992 (N.D. Cal. 2000)