The US Department of Justice (DoJ) announced today that it has reached a settlement with Microsoft in the government's historic antitrust case against the software giant.

The agreement "imposes a broad range of restrictions that will stop Microsoft's unlawful conduct, prevent recurrence of similar conduct in the future and restore competition in the software market, achieving prompt, effective and certain relief for consumers and businesses," according to a statement from the DOJ.

The 18 states participating in the lawsuit did not agree to the settlement, however, and are requesting more time to craft a reply to the consent decree announced by the DoJ.

Under the agreement, Microsoft must license its operating system to key computer manufacturers on uniform terms for five years. The agreement also bans retaliation against manufacturers electing to use non-Microsoft middleware software.

Microsoft must disclose its middleware interfaces — data used by software developers to write Windows-compatible code — and it must disclose its server protocols so non-Microsoft server software can work with Windows on a PC the same way that Microsoft servers can. The settlement also bans exclusive agreements for support or development of certain Microsoft software.

Key points of the settlement

— A broad definition for middleware products, including browsers, email clients, media players, instant messaging software and future new middleware developments.

— The freedom for computer manufacturers and consumers to substitute competing middleware software on Microsoft's operating system.

— Compulsory licensing of any intellectual property necessary for computer manufacturers and software developers to exercise their rights under the deal.

— A panel of three independent, onsite, full-time computer experts to assist in enforcing the settlement, with full access to Microsoft's books, records, systems and personnel, including software source code.

The US Supreme Court has already denied Microsoft's appeal to overturn Judge Jackson's ruling that the software maker violated antitrust laws by holding a monopoly in the PC operating systems market.

Although it still faced the threat of remedies, Microsoft in September escaped the threat of being split into two companies when the DoJ announced that it was dropping its breakup effort to focus on restricting the company's business practices.