The world of open source is moving ever further from its unpaid volunteer roots. The past year saw the $420 million acquisition of JBoss, as well as a Microsoft-Novell deal that tested the legal limits of commercial open source.

With the momentum of a freight train, open-source technology spread more widely in the software industry in 2006. Upstart challengers, such as open-source database company MySQL and middleware maker JBoss, grew rapidly over the course of the year, while incumbent vendors dealt with the open-source effect in different ways.

Perhaps the most dramatic events of the year were Microsoft's attempts to come to terms with open-source products and development techniques. The highlight was a deal with Novell to improve interoperability between their respective products.

With the ink barely dry, though, the two companies got into a spat over a patent protection arrangement, with Novell's CEO sending a letter to the open-source community claiming that a patent payment between the companies did not indicate any legal liability on the part of Novell or its customers.

Legal experts asked whether the deal conforms to Novell's open-source license, while other free-software and open-source adherents panned the legal agreement as unacceptable.

Oracle, which had been rumored to be interested in acquiring JBoss, entered the Linux business by offering Red Hat customers direct support--at less than half of Red Hat's price.

That initiative, along with the Microsoft-Novell deal, turned up the heat on leading Linux distributor Red Hat as it sought to expand through its acquisition of JBoss.

Oracle made a few other efforts to boost its standing in the open-source world. After buying a small company closely linked to MySQL, it purchased embedded database provider Sleepycat. It even offered to buy MySQL itself but was rebuffed.

IBM, feeling competition from open source, decided to make its DB2 database free of charge, in keeping with moves made by Microsoft and Oracle.

Meanwhile, Sun Microsystems finally released the source code to its implementation of Java, after years of internal debate and requests. The main surprise was the choice of license: the General Public License, which is used with Linux and many other open-source products.

The GPL itself is getting an upgrade to version 3. Early in the year, its authors presented the proposed changes, which included stricter limitations on software patents and digital rights management. The changes were not universally well-received; most of the Linux kernel developers gave it poor marks.

In the development tools area, open source has become de rigueur. A number of tools-related initiatives were launched, such as the Ajax Toolkit Framework, which aims to bring Ajax-style development to the open-source tool framework Eclipse.

And Adobe Systems announced that it would contribute its script virtual machine to the Mozilla Foundation for inclusion in future Firefox browsers.

--Martin LaMonica

2006 Highlights

Public debate on GPL 3 draft begins

Free Software Foundation releases the first public discussion draft of the General Public License version 3.

IBM sets DB2 database free

DB2 Express-C is a free version of IBM's flagship database aimed at winning software developers over to its products.

IBM spearheads Ajax tools at Eclipse

Open Ajax is a proposed open-source project to let programmers build Web apps using Eclipse, Ajax toolkits.

Red Hat scoops up JBoss

Ending speculation, Linux distributor shells out $350 million for open-source Java company.

Novell brands its own open-source religion

To perk up revenue from open-source software, Novell readies an open-source identity-management package and desktop Linux suite.

Open source shapes up as rival to Oracle

Software maker's stronghold in databases likely to come under threat from open-source competitors, IDC and Gartner predict.

Microsoft bends on OpenDocument

The software giant will sponsor an open-source project to create a converter between Open Office XML and OpenDocument file formats.

Microsoft gives go-ahead to open-source Web services

Company won't assert patents related to 35 Web services specs--a move designed to ease developers' legal concerns.

Oracle to offer Red Hat Linux support

Announcement marks the first time a major computing company with Linux ties will compete directly with the Linux seller.

Microsoft makes Linux pact with Novell

Former software foes pledge to work together to help Windows world and Linux world interoperate.

Adobe to donate script code to Mozilla

In the largest code handoff since its formation, makers of Firefox will get Adobe's script virtual machine.

Sun picks GPL license for Java code

After years of requests and debates, Sun is set to release Java source code under a Linux-friendly license.

French parliament dumping Windows for Linux

Study by technology services company convinces the National Assembly that the switch will be cost-effective.