When I first saw that Canonical, Ubuntu's parent company, was dumping the X Window System, which is the networking windowing system that's the foundation of almost all Unix and Linux graphical desktop, for Wayland, an OpenGL-based display management system, I wondered if other Linux distributors would follow. After all, everyone in Linux graphics circles had one or more beefs with X-too complicated, too slow, too filled with archaic junk and so on. On the other hand, everyone in Unix circles had also been using X since the late 80s, long before Linus Torvalds started work on Linux. Could people really give up X that quickly? You betcha! Fedora, Red Hat's community distribution, has also decided to start to move to Wayland too.
After the recent Linux Plumbers Conference, a gathering of core Linux developers, Fedora's "graphics cabal," Adam Jackson, Kevin Martin, and Dave Airlie decided that while Wayland wasn't ready yet, with work, Fedora could, and should, use Wayland in place of X for its graphics stack.
Jackson wrote on Fedora's developers list that while "Wayland's not a usable default yet. It'll probably be packaged in F15 [Fedora 15] as something you can play with. We don't even have a complete list of transition criteria yet, let alone a time-frame for switching the default. But it's likely to happen eventually because it's a serious win for a lot of things, and the downsides are pretty negligible despite the fear from the peanut gallery." Fedora 14 just came out. Fedora 15, which is the first version of Fedora that would include Wayland, is due out on May 10th 2011.
Some Fedora users, however, believe that the downsides, especially those that would affect remote desktop and client networking are really quite big. In another note, Jackson laid out these concerns and responded to them:
- We lose network transparency! Well, sure, the protocol doesn't have that directly. You can still do vnc-like things trivially and with a modest amount of additional wayland protocol (or just inter-client conventions) you can do spice-like things. This is good, not bad, because efficient remoting protocols do not look like X. Now we get to design a good one, and in the meantime vnc-style remoting sure does go a long way towards being good enough. (But, we can't switch yet, because we don't even have vnc-style remoting yet; so we're not switching yet.)
- We lose support for older hardware! Yep. Here's a nickel. We have sufficient kernel support for this for the big three hardware vendors, and we're probably going to see more ports to the marginal hardware in the next year or two. Losing <1% of the hardware support isn't keeping me up at night. (But, we can't switch yet, because there's not a good fallback design to classic X on that kind of hardware, and it includes things enterprisey people run on; so we're not switching yet.)
- All my X apps have to be ported! Yes, if they want to be native wayland clients, they do. If they don't, you can run a nested X server like on OSX. They'll still work as well as they ever did, and you even get to keep ssh [Secure Shell] forwarding of them. You can run a wayland server that does nothing but run a nested X server and you wouldn't ever know the difference. Except of course that your shell and your screensaver can be wayland apps, which means your screen locker will still work even if an app has a menu open, and you can actually do secure password input.
It's not just that Wayland needs more work and that X and third-party programs would need to be ported to Wayland. As DJ Walker-Morgan, editor-in-chief of The H and programmer said, "I know folks are excited about Wayland, but I hope no one's forgotten it'll need an open standard/spec, not just a GPL implementation."
He's right. We do need something better than X, and Wayland probably is it. But, and this is a bit "But," the details of how it will work as an open-specification still needs to be spelled out. In addition, Wayland needs a lot more development work. It's going to be interesting to see how it all works out.
Personally, I don't see any Linux distribution using Wayland as its default graphical interface until well into 2012. I also think it's possible that a cleaned-up and revised X server may yet keep X as Linux's dominant graphical interface. For now, though, Wayland's star is in the ascendent and the venerable X Window's star is descending.