Four months after Intel promised to begin offering Linux support for its popular Centrino set of laptop chips, the company on Friday released pre-production drivers for the 802.11g-capable version of Centrino.

The "pre-beta" software, including driver source code and binaries for firmware, allows the Linux operating system to interact with the basic functions of the Intel Pro/Wireless 2200BG Network Connection chip - the Centrino component handing both 802.11b and the faster 802.11g signals.

It is available on a SourceForge project page, here. Pre-production software for the 802.11b-only component, the Intel Pro/Wireless 2100, was earlier released, also on SourceForge.

Intel cautioned that the code is only for the use of technical developers "and not the general Linux population". They do not support all the features handled by the Windows drivers, and some of the features they do support - such as power management - will only work with the latest version of the Linux core, 2.6, which hasn't yet made its way into the flagship enterprise products of Red Hat and Suse. The drivers allow Linux laptops to take advantage of the 802.11g's 54Mbit/s bandwidth, up from 802.11b's 11Mbit/s.

The Centrino chipset, with its power-efficient Pentium M core, has been the focus of a massive advertising campaign that many in the industry say created the current laptop sales boom. However, Windows is the only operating system that can take full advantage of the chipset's most attractive features, such as built-in wireless networking and advanced power management.

A recent OSNews review of a Linux-certified Centrino laptop running Xandros Desktop 2.0, for example, found that wireless networking often didn't work, and that "sleep mode" wasn't available.

Such problems are the result of hardware makers' reluctance to offer full support for Linux, often for fear that if they release their drivers under open-source licences they will lose control of proprietary technology, according to industry observers. In January, Will Swope, general manager of Intel's Software and Solutions Group said Intel was concerned about revealing secret intellectual property and would consider first releasing a proprietary version of the drivers.

Intel's support is a step forward - in many cases Linux developers must still create their own hardware drivers for graphics cards, printers and other basic components. This is still the case for anyone who wants to use Linux with the 802.11a version of the Centrino chipset, as Intel isn't planning Linux support.

Intel said it has appointed a public maintainer for the two Centrino drivers - ultimately intended to become a single unified driver - who will feed suggestions from the community back into the project. "These drivers are meant to provide the Linux developer community a chance to improve and provide feedback for the driver," Intel said in a statement.