In all the articles this past month about GNOME 3 and Ubuntu's Unity, video drivers have received only passing mention. Yet video drivers (or their lack) could not only determine each desktop's success, but also be the area where each has the most influence on Linux and free and open source software (FOSS).
Specifically, I'm referring to the fact that drivers with 3-D hardware acceleration are required by both GNOME 3 and Unity. Whether each development team decided on this requirement separately, or whether one decided that it must match the other in sophistication, will probably never be known. But the fact remains that two of the leading desktops now require what, for FOSS, is advanced -- at times, even bleeding edge -- technology.
This requirement is a problem for two reasons. First, in general, FOSS hardware acceleration lags behind that of other operating systems. Video drivers is an expert's field, but, Phoronix's Linux Graphics Survey in September 2010 suggests that more or less reliable hardware acceleration is available only for 72% of Linux desktops -- those using Intel, Catalyst/fglrx, and NVidia drivers. (And many would quibble about the reliability of each of these drivers).
That leaves 27% using the free drivers for ATI, Radeonhd, and Nouveau, each of which has some degree of hardware acceleration, but might be unreliable in any given combination of hardware. It also leaves about 1.5% using the long obsolete VESA driver.
Second, of the drivers that do support hardware acceleration, only the Intel ones have a free license. That leaves free software supporters (whatever their numbers might be) with the choice of either abandoning their principles and using a proprietary driver, or else of looking for an alternative to GNOME 3 or Unity.
The first issue is acknowledged indirectly by the fact that both desktops include a fallback option of a desktop based on the GNOME 2 series with less demanding hardware requirements.
At first, GNOME tended to downplay the issue, claiming that GNOME 3 uses "relatively primitive 3D capabilities that have been available from essentially all computing devices made in the last 4 or 5 years."
However, by the time GNOME 3 was released, the FAQ acknowledged the problem, adding that "The GNOME project and its partners are working hard to ensure that the complete GNOME 3 experience is available to as many people as possible, and aim to ensure that users who are initially unable to have this experience will be able to in the future."
By contrast, Ubuntu makes no mention of the requirement on its download pages, presumably assuming it is not an issue. Neither GNOME 3 nor Unity mentions the licensing problem in any prominent place on their websites.
However, neither problem disappears for users, regardless of what is officially discussed. The problems will most likely disappear in the next few years as work on free-licensed drivers continue, but, for now, requiring hardware acceleration seems premature.
In fact, you have to wonder whether the decision to rely on hardware acceleration was a miscalculation. Maybe both development teams over-estimated the rate of driver development, assuming that hardware acceleration would no longer be a problem by the times of the official releases.
If nothing else, it seems worth noting that, in developing Firefox 4.0, Mozilla dropped the need for hardware support for the Linux versions, describing the state of free-licensed drivers a few months ago as "disastrously buggy." But then, Mozilla has always supported free licenses, and the 3-D demands are undoubtedly greater for a browser than for a desktop.
Still, Mozilla's example brings up another question: Why is hardware acceleration needed for a desktop in the first place? Functionally, there seems no reason for it, and users hardly seem to expect it, or so many would not be considering alternatives like Xfce that lack it.
If the main purpose is eye-candy, both Unity and GNOME might have learned from the KDE 4 series. For all KDE 4's sometimes unpopular innovations, its basic functionality is available to all users, and hardware acceleration is required in the KDE 4 series only for some of the optional special effects.