[dot] aKademy 2007: The Second Day

[Dot Stories]

URL: http://dot.kde.org/1183570401/

From: Jos Poortvliet <>
Dept: sunday-is-the-fun-day
Date: Wednesday 04/Jul/2007, @10:33

aKademy 2007: The Second Day
============================

   aKademy 2007 [http://akademy2007.kde.org/] continues! Sunday, the
second day of the conference, brought more talks covering a wide
diversity of topics. Read on for the Sunday aKademy 2007 Report.

     Sunday was very busy and interesting, and we regret that we were
not able to attend and cover all talks. Yet, we reported some of the
most interesting. Luckily, you will be able to find sheets and videos
[http://akademy2007.kde.org/conference/programme.php] of the talks on
the aKademy 2007 [http://akademy2007.kde.org/] website. Lubos Lunak
about Compositing in KWin
     Lubos starts by explaining that his talk will comprise two parts:
first he will cover the 'boring' part, then continue talking about the
'other' part. Starting with the boring stuff, he explains how
compositing works and what it is useful for.
  Konqi composited over other windows

A. THE 'BORING' PART

     Normally, windows are asked by X to paint only the parts which are
actually visible on-screen. Parts of windows which are obscured by other
windows or outside the visible screen area are not painted. In
compositing mode, all windows are always fully painted to an off-screen
bitmap, and then painted on the screen. The composition manager can do
something with the windows before they are painted, like add shadows,
transparancy, rotate them, let them explode or draw them multiple times.
Also, windows which are not painted for some time can still be moved
around, without turning into a white blob - the window contents are
still in the off-screen buffer. Windows also don't need to repaint all
the time when you move them. Of course, there are disadvantages - each
window needs to actually be in the off-screen buffer, which uses video
memory. And the drawing process can be slower as well, even if all
effects are turned off.


B. THE 'OTHER' PART

     So, how to use all this? Technologies like XGL and AIGLX are used
to do the compositing. From Lubos' point of view, they are equivalent -
just with different bugs. Lubos started the kwin-composite project in a
seperate branch, as he expected to de-stabilize KWin greatly. Things
turned out to be a lot better, and in hindsight, he wouldn't have needed
the seperate branch. The compositing stuff doesn't effect the 'normal'
mode of KWin in any significant way.

     KDE 3.x already had compositing, based on the (not so powerful)
XRENDER extension of X.org. With the composite, XGL and AIGLX
technologies, real compositing is now possible, and several experiments
are going on in this area - think of Compiz and Beryl. They mostly focus
on fancy effects, and Lubos decided it was better to add compositing to
a mature window manager than window manager to a compositor - hence the
work on KWin. Lubos then goes into some rather technical details, and
then points out the current status. There is a mostly-stable API for the
effects, which makes it pretty easy to write plugins - you often don't
even need to know OpenGL or XRENDER stuff. He shows us a zoom-in example
created from 50 lines of code. KWin itself is mostly stable, and there
are some cool plugins, but there is also a lot of work to do on the
actual look-and-feel. Lubos wants to focus on the usable, rather than
primarily 'cool', and he needs some help writing useful plugins. So if
anybody with graphic design skills is willing to give him a hand, Lubos
would be appreciative!


  I. JOSEF SPILLNER, GHNS2 AND GAMES

     Josef held a talk about collaborative data sharing and briefly
touched on games.

     Currently, KDE has the GetHotNewStuff
[http://ghns.freedesktop.org/] framework, which is capable of uploading
and downloading user data. Most applications only use it for
downloading, though. The framework is missing several needed features,
so for KDE 4, work has started on a GHNS2. This is being done in close
co-operation with FreeDesktop.org, though unfortunately GNOME isn't
particularly active in this specific area of the platform.

     Currently, GHNS2 consists of over 3500 lines of code on the server
side, offering all the necessary infrastructure for handling uploading
and downloading, metadata (like ratings), and even has a versioning
system. It is not yet complete, as there are a lot of additional
functionality requests from application developers, but the latest SVN
version has already incorporated most ideas, and the GHNS2-hackers are
looking for more input and comments. Feedback from the KDE-Edu
[http://edu.kde.org/] and KDE-games [http://games.kde.org/] developers
has already proven very valuable, and a lot of work has been done on
account handling, OpenID integration and security. There are also
initial proposals for desktop-wide single-sign-on, so we'll see a lot of
great things in these areas throughout the KDE 4 lifecycle.

     Of course, on the client-side, work has been done to support all
new server-side things, as well as creating an easy-to-use API and a
flexible configuration system. Josef explains that the needs of
applications can differ enormously, thus such configuration elements are
important, as is the simple API.

     Currently integrated and (mostly) working are uploading and
downloading, with some dialogs and buttons already available to use in
the interfaces of applications. The backend stuff is mostly ready, but
there is still a lot of work to do in the GUI area. Josef also tells us
there will be close Plasma integration, and some Plasma-related work has
already been developed.

     He continues to talk about the specifics of the architecture and
the API. As said before, the API has been carefully designed to be as
easy as possible, and almost all basic tasks can be done in just one
line of code, yet the system allows for very fine-grained control for
those who need it.

     Another new feature is the sharing of data between applications,
made possible by the seperation of GHNS2 and application configuration.
Josef continues to show us screenshots of several predefined interfaces,
including cool 'tag clouds', and explains how they developed a a
'daemon' mode. This allows for web services and Strigi integration.

     According to Josef, the community around GHNS2 is very active and
innovation is happening at an impressive pace. By closely collaborating
with the applications which need GHNS, great ideas are turned into code
quickly. He calls for even more ideas, so everybody who can potentially
make use of the GHNS2 framework are urged to get into contact!

     Josef uses the last few minutes of his talk to tell us about the
GGZ system being built by the KDE Games community. Their idea is to
allow casual online gaming: simple, good-looking and addictive games,
easy to play online against other people. To consolidate the protocols
and file formats, they are again working with FreeDesktop.org to ensure
GNOME apps will be able to interoperate and play with the KDE apps.
Encouraging multiple implementations will ensure the API's are sane, and
allow for a lot of progress in a relatively short time. The foundations
are laid, the big work left to do is on the GUI: creating widgets for
the new features, and integrating them into the applications.
  Eyecandy for KDE...

 II. TOWARDS A SEMANTIC KDE

     Tudor Groza, a researcher from the Digital Enterprise Research
Institute [http://www.deri.ie/], explained the technical and social
aspects of the Semantic Desktop efforts at the Nepomuk project. Starting
with the history of semantic research (which started in 1945!), he
explained that technical limitations ensured that the social desktop has
not yet arrived. But now most basic of the technology is in place, like
Wiki's, social networks and the World Wide Web, so it's time to start
integrating these things.

     Tudor went into the architectural details of the semantic desktop,
focusing on the RDF technology and explaining what ontologies are.
Ontologies are shared conceptualisations, defining concepts, relations
and properties. RDF is the method of expressing them, and it is actually
very simple. A RDF statement consists of triplets, each having a
subject, a predicate and an object. For example, you can have:

Subject: John
Predicate: Age
Object: "40"
Or:
Subject: John
Predicate: Likes
Object: Mary

     The difficult thing, and the reason for more research, is sharing
this knowledge, a social semantic web. Getting from personal information
management through distributed information management to a real social
network is a huge step. We do have the seperate technologies for this,
like p2p applications, social networking sites, natural language
processing tools - but we need to combine them. We now have a Semantic
Desktop, but in time, it will evolve into a Social Semantic Desktop.

     This has the potential to accelerate collaboration, people can
maintain shared views in a global network, but also create
sub-communities. It will further the sharing of knowledge and data,
which is crucial in this era of information explosion, but also a
growing gap between the light of knowledge and the darkness of
misinterpretation.

     The Nepomuk project, funded with 11.5 million euro by the European
Union, consists of 16 different organizations. These range from big,
commercial players like IBM, through to universities and smaller players
like Mandriva - and of course, the KDE project. Their goals are
defining, standardizing and implementing metadata creation and sharing.


A. NEPOMUK-KDE

     Tudor showed a few mockups and screenshots of what should be there
and what is, and then delved further into what they are building for
KDE. The foundation is there now, after the creation of a shared
metadata storage with standardized ontologies. Work has begun on basic
integration in some KDE applications and getting the Nepomuk
technologies into the KDE core libraries. Then tools to analyze and
search metadata have to be written, and finally work will begin on
linking data from several sources and sharing the metadata.


B. CONCLUSION

     The Nepomuk developers enjoy working with the KDE community -
according to Tudor, we are a very open group of people. Yet, introducing
new technology goes slowly, and people can best be convinced to use it
if it solves current problems, rather than just providing something
which is part of some distant vision.

     On Thursday, a BoF session will be held, talking about the usage
and implementation of Nepomuk in KDE applications, and several hackers
expressed interest in attending.


III. OTHER TALKS

     There where many other talks, ranging from KDE platforms talks by
Holger Schröder (Windows), Benjamin Reed (Mac OSX) and Stefan Teleman
(Solaris), talks about several distributions like Gentoo, Fedora and
Kubuntu and a lot community talks. You can find sheets and videos
[http://akademy2007.kde.org/conference/programme.php] of the talks on
the aKademy 2007 [http://akademy2007.kde.org/] website. Don't forget to
check it out!


 IV. AKADEMY AWARDS

     At 6 pm, the aKademy Awards ceremony started, presented by 2 of
last years winners [http://dot.kde.org/1159194107/], Laurent Montel and
Boudewijn Rempt.

     Like Saturday, it was a productive and interesting day, and the
hackers are looking forward to the rest of aKademy. The network started
to work around 2 pm, during the keynote by Jim Zemlin
[http://dot.kde.org/1183385741/]. Immediately, many became connected to
cheers and applause.