A US judge has ordered software giant Microsoft to include Sun Microsystem's Java programming language in its widely-used Windows operating system.

The order is to remain in force pending the final outcome of a lawsuit brought by Sun Microsystems against Microsoft.

Sun claims that the software giant tried to marginalise Java by making a recent version of Windows - used on 90% of the world's personal computers - much less compatible with the programming language.

US district judge J Frederick Motz agreed to impose the preliminary 'must-carry' order against Microsoft at Sun Microsystems' request.

Judge Motz said Microsoft had "leveraged its PC monopoly to create market conditions in which it is unfairly advantaged."

Edged out

The Sun case is one of four brought by competitors in the wake of Microsoft's long anti-trust suit with the US government.

The company was found to have abused its monopoly position, although the remedies were watered down extensively in a court ruling this year.

At stake for Sun is the future of Java, Sun's cross-platform programming language.

Java was created so programmers could "write once, run anywhere" - in other words, create programs which were not dependent on the user's computer using a specific operating system.

Microsoft has opposed Java for years, fearing it could eat into its Windows monopoly over the desktop, and made sure the Java included with Windows would not work properly with other operating systems.

Initially it refused to put Java in its Windows XP system released last year, but has since said it will include its own version - although only until 2004.