The three immediate design stakeholders in the ‘enterprise desktop’ are: end users, help desk staff, and desktop system administrators. Most design work for GNOME has gone into improving the end user experience, which is really the dominant stakeholder of those three. Some improvements aimed at end-users, like promoting preferences instead of settings you can get wrong, have also made life a little easier for help desk staff (as people are that much less likely to hose things). Recently Mark’s work on Vino has added a very large improvement for help desk staff: the ability to remotely view and operate user’s desktops (there is nothing more frustrating than blindly stepping people through computer operations over the phone).

So what about sysadmins? Sabayon is GNOME’s first major design targeted at improving the user experience for people who administer GNOME systems, and hopefully the start of an initiative toward designing for this important group of users. I’m jazzed about Sabayon as the first step toward a historic goal: GNOME as the definitive desktop management experience for sysadmins. We have a long way to go, but if there’s a hundred possible improvements to make over Windows and MacOS/X toward the end-user experience, there’s a thousand for admins. But big things start with small steps, right? I see promise for Sabayon as the ground floor of the revolution! <seth takes a deep breath and returns back to earth> In any case, whatever the future holds, this is fertile territory because the status quo is so much worse than it needs to be.

GConf, with its support for mandatory settings and system defaults, was supposed to be a big improvement for system administrators, but it ended up being something of a boondogle because the features were hard for sysadmins to use. In most cases it actually made things harder as sysadmins struggled through the giant XML files for defaults (most probably tried to edit schemas instead, which isn’t even the right thing, but its not their fault because we didn’t publicize this well). Even apart from the XML files being long and verbose, remember that most sysadmins in the world (think Windows), esp. desktop sysadmins, are not uber-leet Unix haxors who adore vi and the command-line.

Speaking of leetness, two super-leet Red Hat desktop hackers with funny accents are kicking off work on Sabayon: Mark McLoughlin (panel maintainer, etc) and Daniel Veillard (libxml & gamin maintainer). There was a tuffle over the name, but the French (what with their centuries of cultural sophistication and all) beat out the elves. As Mark explains it, DV probably just wanted to be able to say, “Hello I’m Daniel Veillard and I pronounce Sabayon ‘Sa-ba-yon’”. Our Irish hackers really are like little elves that write code. You go to bed and when you wake up in morning a bunch of code has magically appeared. In retaliation, I was assigned the mythical character of a “Troll” by DV, but this does not hinder my speaking the truth. I may be a troll, but I am a truthful troll. The only thing that serves to dampen Mark’s elf-nature is when he lights up like a chimney stack, strangles me with scarves, whacks me with bats, drives through red lights and otherwise engages in behavior liable to result in death. But back to Sabayon.

Humble Beginnings, What Sabayon Does Today

First and foremost, Sabayon provides a sane way to edit GConf defaults and GConf mandatory keys: the same way you edit your desktop. Sabayon launches profiles in an Xnest window. Any changes you make in the Xnest window are saved back to the profile file, which can then be applied to user’s accounts. Want to add a new applet to the panel? Right click on the panel and add one just like you usually would. Of course, you’re also free to use gconf-editor to change keys at a lower level, or download any GNOME setting tweaking program from the internet and use that. Sabayon also uses gamin to watch changes you make to the filesystem. So if you want to change the font for your users, you can drag a TTF to ~/.fonts, change it in “Font Preferences”, and voila. When you’re done making changes, you can save the profile. A change log will automatically be generated so an organization with a number of sysadmins can track down what changed when. Hopefully in the future we’ll also have revision support for desktop profiles.

Right now Sabayon has support for tracking: GConf settings, panel applet addition/removal, general files and special Firefox profile support.

The Illustrated Tour of Sabayon HEAD

1. First we launch Sabayon (if a non-root user it uses console helper to get root).
   
2. Lets create a new profile for panty-waist designers. We base it off our existing Office Desktop profile.
   
   
   
3. Sabayon starts an instance of that profile in an Xnest, including the sabayon monitor window.
   
   
4. Designers need to be coddled, we create a welcoming text file for them and save it to the desktop.
   
5. In response to saving the new text file, two new entries appear in the sabayon monitor. We don’t actually want to change the recently used list, so we tell sabayon to ignore that setting.
   
6. We drag a new Gimp launcher to the panel. Gimp is like crack for designers.
   
   
7. In response to the new launcher, sabayon monitor shows some new entries (and I have a continuity error in taking screenshots, there should still be the two items for creating the text file because we haven’t yet saved, oops). Notice that Sabayon records a “Panel object added” change rather than a dozen GConf keys being added. Sabayon can be taught to aggregate standard groups of changes together to make it clearer to admins what’s going on when they read through the change log.
   
8. Designers like pretty things, lets change the background. (As a total aside… the background capplet rewrites its GConf keys constantly a couple times a second whether they have changed or not, which makes the sabayon monitor flash a bunch in the background. The monitor has been interesting in revealing a lot of apps that are setting keys / saving settings files at weird times, which would be sucky in a networked environment)

   
   
   

9. And, as expected, the Sabayon monitor shows a bunch of GConf keys being changed. We’ve also gone ahead and checked the keys for adding the Gimp launcher to be “mandatory”. That means users that have this profile applied will be unable to remove the Gimp launcher. Unexpectedly, there’s a bunch of “.fonts.cache” files in the list too. Sabayon has a list of files and directories to ignore, but its not complete yet. For now, some operations will generate a bunch of file change noise.

   

10. If we just quit now, the all-in-one Desktop Designer.zip profile in /etc/desktop-profiles would not have been updated. If we’re happy with the changes, we can save them back to the profile.
    

11. The profile can then be distributed to computer(s) and applied to the relevant user’s homedirs. We haven’t started working on the mechanisms for this yet, Sabayon is the first piece in a bigger framework. For example, once we get the Netscape directory server code released and have a robust free ldap server, we can potentially host e.g. the GConf settings there and push to the server instead of applying bits to actual hard drives (or NFS shares).

    In the interim, the SabayonProfile class already knows how to apply profiles onto a directory. Actually, every time you edit a profile, a new temp directory is created first, and the profile is then applied to it. Consequently, it should be pretty easy for sysadmins to cook up their own python scripts using the SabayonProfile class that work on their custom systems today.

To Infinity, And Beyond!

Sabayon is just the first step in improving the manageability of GNOME. We (well, I) wanted to get something concrete landed that will help us focus on sysadmins as users, rather than designing a bunch of abstract features. It also exposes manageability features GNOME has theoretically had, but never exposed in a way people could easily exploit, which is good. I’m rambling now, again, but here are some random things markmc, dv and jdennis might be working on in the future:

• Making sabayon solid. Its still a very young project (its one month birthday is tomorrow), and is rather rough around the edges. Things are falling into place pretty quickly now, but there’s a lot of work still to go just in making the current feature set work better. Some simple improvements like expanding the “ignore changes to these directories” list will make things a lot better. We also have a number of UI features that aren’t in the current codebase.
• Supporting revision history on profiles
• Figure out how Stateless Linux (in a nutshell, where the root partition is mounted read-only and synched transparently with a central source, giving the central-state advantages of thin client with the low hardware and network infrastructure costs of cheap-intel-box thick client) and Sabayon work together. Stateless Linux makes it easier for one admin to support many machines. Sabayon (particularly sabayon of the future) will make it easier for one admin to support many users. The intersection of these two is a very nice place to be!
• We might try to figuring out a short term solution to distributing profiles to user home-directories (whether those be on an NFS share or spread across a couple dozen computer hard drives).
• A real icon and a logo, because self-respecting GNOME projects these days need kewl logos from day one. By showing the world the icon I barfed up (), Diana will be forced to make us a new icon, pronto. Designers can’t stand ugly graphics.
• Backing GConf with some sort of network store, perhaps LDAP. If we could get a drop in and run GConf server using the better-be-freed-soon netscape directory code, that would be awesome.
• Reducing the pain of panel management and upgrading by moving to a new layout/storing model where applets are either “on” or “off”. Panel cursors allow control over where applets go. This means adding/removing/changing applets in upgrades becomes possible. Currently it breaks everything, which is a management nightmare for distros, let alone the lone sysadmin
• Figuring out how to improve managebility of the Frankendesktop (word thanks to Luis). OO.o and Firefox mean that GConf support alone isn’t enough for now. But if we’re tied into supporting all these systems, we may never have the ability to do something as nice and universal as Windows group policy. So one project is to figure out if we can back OO.o and Firefox preferences using GConf. Then we can support GConf with all our heart, soul and mind in the tools and on the server.
• Extend GConf to support features that allow small numbers of admins to support hundreds or thousands of users (such as group policy). We don’t just want to copy giant technical architectures blindly, and we haven’t started looking into this design yet, so its very vague for now.

Getting Sabayon

Sabayon is a little buggy atm, but its pretty easy to get running . Python source is available from the sabayon module in GNOME cvs. The major dependencies are pygtk and the gamin python bindings (these are available in fedora core HEAD, but gamin-python is not in FC3, I think). I think the GConf parts will still work even if you don’t have the gamin python bindings, but YMMV. You’ll also have to paste in two one-line text files in /etc/gconf/2 as per the README, but its pretty easy.

And now for a less sexy blog post. I just sent this message to desktop-devel, but as per the message, I know many GNOME hackers no longer read lists completely, soooo….:

Revitalizing the Urban Center of GNOME

We need to get desktop-devel back to the useful hacker exchange it once was (probably only in the soft glow of memory, but hey). That means not only do GNOME enthusiasts need to be more restrained, but we (the core hacking community) need to get back on the list, start using shared channels like #gnome-hackers (even for hacker-to-hacker social purposes) again, etc.

Forward: For a drawn out post on next-generation X rendering, this blog entry is really short on eye candy. I apologize, but I’m at home, separated from my beloved eye candy, and figured I should write this while I felt motivated. As a way of forcing my own hand, I’m making a link now to a blog entry I haven’t yet written that will contain screenshots in the future

Next-Generation Rendering For the Free Desktop

For the past half year or so Red Hat’s desktop team has had people working toward making accelerated graphics rendering on the free desktop badass, but doing an ass job of actually talking about what they’re doing in a larger public / GNOME context. They’ve been doing a combination of experimentation (from that cracktastic OpenGL compositing/window manager luminocity to xsnow for the Xcomposite generation) and knuckle-down no-holds-barred infrastructure work (like making Win32 GTK work on Cairo so GTK can move to cairo as the default backend). With RHEL4 kicked out the door we’ve been able to rebalance day-to-day work on GTK and X onto other people to give the nextgenren hackers free hands. Currently the full-time nextgenren team at Red Hat is Owen Taylor (gtk/pango maintainer), Søren Sandmann (x hacker), Diana Fong (visual designer), Kristian Høgsberg (x hacker) and Carl Worth (cairo maintainer).

I’m really excited because these guy’s expertise is across a broad chunk of the rendering pipeline, from the toolkit down to the x server, which is going to give this effort the ability to work on this from a global perspective rather than optimizing the bits where we happen to have influence in. I’m doubly excited because other companies (well, Novell at least, but hopefully others will join) are starting to invest in this effort too!

I’m hoping to drag Owen into spinning this off into an umbrella effort (ala project utopia) to help maintain a coherent story/platform even as lots of people pour work into lots of different packages and distros. There are so many different ways to attack the X rendering issue that I’m a little worried about seeing a lot of fragmentation of effort and the result not being particularly coherent. I do hope people experiment with lots of different approaches, but I also really hope that in we can give developers a consistent platform for doing cool graphics on the free desktop. It would be a real shame to end up with the message in two years being “well, platform X has the feature you want, but you have to worry about also working with Y because X won’t work well on distro Z”. This sort of technology-choice morass can really dampen developers playing with this stuff and adding support all over GNOME, which is exactly the sort of quick-fiddling big-payoff stuff I think we’ll see a lot of as soon as this stuff starts landing. In other words, lets push toward the point where people can feel confident and start hacking up cool things for this system inside GNOME.

What It Might Look Like

A really good system needs to have lots of pieces in place all hooked together….its not something that can be hacked apart and replaced by arbitrary random incompatible bits (though there are points of commonality, such as OpenGL or Render). For example the pieces in one imaginable architecture – by no means the decided-upon final one or anything – might look like:

• A sophisticated drawing layer (cairo using glitz/opengl or render as backends)
• Stock renderers built on top of that drawing layer (pdf/ps rendering backed by cairo – such as Alex Larsson’s xpdf fork in evince, svg rendering backed by cairo, etc)
• A toolkit that agressively takes advantage of the features in the drawing layer, exposing them to applications and themes (gtk+)
• A window+compositing manager that can work closely with the toolkit but essentially takes the window contents as a static image in compositing (metacity with luminocity-like GL compositing manager features fused in to deal with window effects, synching up smooth resizing, live window thumbnailing, crazy pagers, etc)
• A hardware driver system to expose a low-level hardware accelerated rendering path to the drawing layer (opengl or render with hardware accel)

With that model we can implement things like:

• Toolkit themes that draw with layer blending effects, delightful bezier curves, and irritating alpha gradients
• Indiana Jones buttons that puff out smoothly animated clouds of smoke when you click on them
• Alpha transparency in applications whenever and wherever the urge strikes us
• Live window thumbnails
• Hardware accelerated PDF viewers
• Hundreds of spinning soft snowflakes floating over your screen…. without messing up nautilus
• A photograph of a field of long dry savanna grass as your desktop background… where the grass is gently swooshed around by a breeze created by moving your mouse across the background
• Windows that shrink scale and move all over the fucking place with cool animations
• Synchronized smooth resizing so there’s no disjunct between window borders moving and the contents redrawing (you should see the demos of this in luminocity… it really makes a difference in how real the interface feels, just as double-buffering did for stuff moving)
• A shared path between on-screen display and printing (using Cairo’s PDF/PS backends)
• Vector icons with very occasional super subtle animations rendered in realtime…a tiny fly which buzzes around the trash every several minutes, etc… think mood animations as in Riven (which as a total random aside is still a shockingly beautiful and atmospheric game years after it came out, postage stamp sized multimedia videos notwithstanding)
• Workspace switching effects so lavish they make Keynote jealous
• Brush stroke / Sumi-e, tiger striped, and other dynamically rendered themes where every button, every line looks a little different (need to post shots / explanation of this stuff, but another day)
• Progress bars made with tendrils of curves that smoothly twist and squirm like a bucket of snakes as the bar grows
• Text transformed and twisted beyond recognition in a manner both unseemly and cruel
• A 10% opaque giant floating head of tigert overlayed above all the windows and the desktop.
• etc etc. In short: awesome.

And that’s a conservative approach to this: each window essentially renders into a texture which are then combined in a separate rendering pass by the compositing manager. A lot of the work Diana does challenges our assumptions about what this rendering system should be able to do. For example, something as simple as a swoosh that cuts across both the window and the titlebar is currently very tricky. Diana’s work has illustrated something that may be obvious, but seems to be forgotten in the excitement to build the One True Graphics Pipeline (this does not exist!): Its very important to figure out many of the things you want to do with the graphics system before you get in too deep and dirty, because there are a lot of directions we could go that call for rather different architectural choices. To give one example, if we decided we really cared about having lots of animations throughout GNOME (this isn’t something we’re pushing, but we talked about it) that would dictate a very different approach from a graphics system where we really really cared about printing. You can’t always have your cake and eat it too… especially not when you consider implementation constraints.

Another example of how prioritizing “what do we want to improve with this” can change the direction: Since taking advantage of these new toys would require a new theme system, Havoc and I have been talking about how a very different theme / widget rendering system might work with this that allows for custom design of any window, widget, or anything in between. One of the things us designers have been experimenting with behind closed doors is what you can do with a window’s design when its not drawn out of a bunch of stock widgets but you have a freer hand. (This does not mean visual inconsistency, just as a magazine can maintain a consistent look but still do a fresh layout for each page using a mix of stock and new elements.) The results can be really good. No matter how good the artist, you can only get so far designing a crude palette of some fixed number of widgets which are then used in preset. A good theme/widget rendering framework would help us negotiate this balance between re-using stock elements, and overriding the rendering of widgets at appropriate points to customize how a “Control Center Preference Page” is drawn or to simply shift the text in buttons over 10 pixels to the left. Figuring out how this stuff works, or if we just want to leave the theming issue alone (which would sort of be a shame given how much of the old flooring we’re tearing up around it), may also have a significant impact on the final architecture.

A radical model (which also avoids multi-pass rendering without opening up security issues present in sharing direct access to existing graphic cards between processes) might involve a centrally rendered scene-graph where each client is given a subtree to add higher-level primitives. That could give us access to candy like pixel and vertex shaders (which we experimented with several months ago as part of rendering subtle but live backgrounds of grass fields, etc), which are attached to nodes on the render tree. Of course, there are many paths for leveraging shaders short of a full scene graph system. The scene graph model has a lot of significant concerns that are not as relevant to, say, 3D games where this model is common. Text rendering is one example.

Owen and company have slides from the X dev conf, but the punks did them as SVGs so unless you have their k-rad Cairo backed SVG slide presentation program, or if you’re willing to view slides in Inkscape… they’re not much good (though it is cool that you can find the slide you need using Nautilus thumbnails, but I digress) (hmmm, you can also open them in eog). Honestly, not the most inspiring OR detailed slides in the world either. I don’t think they’d had much sleep when they wrote them up. *grin*

Anyway… I’m rambling. I’ve given a couple points too much depth, most points not enough depth, many points I’ve missed, and doubtless some I’ve gotten wrong, but I knew if I waited to write the perfect post on this there’d be only more backlog of material to share… so a braindump it was. I guess in the end I’m pretty excited. It feels like we’re running the last couple miles to get to the giant great-rendering payoff Keith Packard kicked off in the X world several years ago.

Code and stuff

• Cairo I think everyone knows about… writing for Cairo in Python or Mono is especially cool. Its really easy to get something that looks good going in short order. If you haven’t played with it, you should!
• Luminocity is in GNOME cvs with the module name ‘luminocity’
• Metacity compositing work is in ‘metacity’ with the branch ‘spiffifity‘
• GTK+ / Cairo integration…. gtk+ HEAD!

Apparently they also have a jhbuild setup that’ll build all this stuff thats headed for CVS in fairly short order.

And for my last point…

Hula!