itsme: a technical overview

Marco Loregian
marco.loregian@itsme.it

Lugano, October 8, 2009

© 2008 by Itsme S.r.l.
All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic,
mechanical, photocopying, recording, or otherwise, without prior written permission of Itsme S.r.l.

About me
Computer Science PhD
- can be translated to “somehow
evoluted geek”
Aware of itsme from the
beginning
Now cross-working different
teams and tasks
- itsme OS software architecture
- itsme emulator
- website mastering
- itsme evangelism
Marco Loregian: itsme from a technical perspective Lugano, 10/08/09

Ajax Architecture Website
GWT Wordpress

Social Concept
Licenses
Computing Emulat
or
Gnome

u nd Naming

itsme
ck
itsme gro
e ba archite Virtual File

a rg
Window System
cture

yl
Managment

ic s
Open

er
Source

V top
Distributed
Front-end

of
KDE resources

lo t ue s
Guglielmo
Architectur
Linux
A is s
e

n)
Metadata

pe
Managem

o
Back-end ent

to f( Metadata
extraction

lo
OLPC RDF

Customizatio
n A Sabayon
Semantic
Interoperabili
ty

Web
Linux

eldy Ontologies
Tracker Semantic Nepomuk Concept
Desktop


The real aim of this lesson is to

discuss our
open issues
with you
No participation = extremely boring lesson :-(


Outline
After introduction, 3 main topics:
- itsme emulator
- itsme front-end
- itsme back-end

for each of them
- background research overview
- itsme approach Roughly one hour

- open discussion
[break]


Before starting, a quick recap
itsme: system embodying a new
metaphor, ‘stories and venues’
Motivation: information overload,
control over data
Target: people creating value with a
PC

New system = new possible ways to
do things with a PC

Main elements to describe the system
Venues
Channels
Resources
Limbo
Transit

...these concepts must be implement
after a deﬁnition given by design

How to proceed?
Concept demonstrators
- Scenarios
- Emulator
- (available at itsme.it)

Technical demonstrators
- Prototypes: UI + meta/data management


What is an emulator?
Software providing the functions of a
system using a different system
Do
yo u
k no
wa
ny
oth
e r?


Speaking of words...
A simulator is something that lets you
experience something as faithfully as
possible
- e.g., ﬂight simulators re-create piloting a plane

Virtual machines provide a system
platform to run software on them
- an OS or just applications, like the Java VM
s e
to ur ca
se a re n o
Th e


Emulator aims
Announced early
Aim: present itsme concept in
advance to a wide audience
- No downloads
- No technical restrictions
Starting from a limited set of features
- Only (at least) two venues
- No Limbo / Transit
- No ‘full’ applications
But what contents?

Idea
Present well-known things according
to the new metaphor (stories and venues)
We added social computing i ts
me
.i t
features to our website…
- personal proﬁles
- fanship
- private messaging
- open publishing
- social bookmarking
Qui
...and then re-presented them ck
t h e de mo
we
bsi of
te
- after some months to establish a community

Website technology
Open source Content Management
System
Easy to use and maintain
Large community supporting the
development, and ﬁxing bugs quickly
Many plugins to extend functionalities
(easy to write)
Easily to implement, customizable
themes

Website customization
A speciﬁc information architecture
(categories and tags)

A set of plugins for the various social
computing features
- some of them were not available when we started,
we had to code them

A tailored theme

Buddypress

...now you could use something like
this, and minimize the effort we
underwent

What we got from the website?
In the end, everything relies on a
single MySQL database
- posts, users, metadata, messages, …

Those data can be showed in a
completely different way, by a
different software
- potentially running anywhere


em
ula
tor
.i ts
me
.i t


Le t
’s s
e ea
de m
o!

Videos and tutorial available at http://itsme.it/emulator


Technology behind the emulator

We considered popular options like
Adobe Flash and Microsoft Silverlight,
but discarded them: guess why…
...and what do you think we used
instead?

AJAX in a nutshell
Until some time ago Web pages
needed to be reloaded to see any
update
AJAX technology allows dynamic,
asynchronous updates
- e.g., facebook notiﬁcations and “show new posts”
Data can ﬂow back and forth between
client and server
The key elements are Javascript and
XML

GWT
Google released a Web Toolkit that
allows to develop user interfaces in
Java and then compile them to
optimized JavaScript
- Allows for better reuse and debug of code
Connection is made to a Web Server
through simple RPC
/
m o: d e mo /
c k de e x t.c om / o y/de v
Q u i t- l
g w c om /de p p.h t m l
w w. x t j s . o
:/ w w.e
/ e sk t
ht tp / w w t o p/d
p: / le s /de s k
h t t mp
e xa

Emulator and Website architecture
Client Product

Web browser
Javascript/HTML

itsme website theme

Custom itsme emulator
Wordpress
Wordpress

http://emulator.itsme.it
Plugins
Plugins
http://www.itsme.it

GWT
Platform

GXT

Wordpress Spring
RSS
JPA javamail Quartz
spider

JDBC driver

Apache Web Server Apache Tomcat
Data

MySql database


Emulator open issues
Envisioning relations

Incremental setup to
- involve user from minute 1
- explain features directly
what to ask in a dialogue?

Other possible ﬁelds or ways of
application?
- Let’s make a “translation” exercise: how would you
frame Facebook in the emulator concept?

What’s an OS?
“An Operating System (OS) is
an interface between hardware
and user which is responsible
for the management and
coordination of activities and
the sharing of the resources of
the computer that acts as a
host for computing applications
run on the machine.”
- (source: http://en.wikipedia.org/wiki/Operating_system)


What’s inside an OS?
You might be familiar with the so-
called “onion skin”
- We’re not redoing everything again!
User

Applications

User
Interface
File
System
Memory

Processes

HW

Sabayon Linux
Italian distribution (we hired its
creators)
Community driven
Style-oriented
Excellent rating
Forst to add cool features such as 3D
effects (Compiz)


The itsme architecture
QT graphical Applications ,
toolkit settings, data

Back End Front End Presentation
New
metaphor
Sabayon
Front-end Logic and Control Linux

Authentication and Security

Linux OS
System and Networking
Migration Support
Proxy
Ubiquitous
access

Data Access
Custom
metadata

Back-end Logic

Data Storage and Persistence

Heterogeneous
sources

As in Jan. ’09: some things have changed...

Open issues
System modularity, ubiquitous
computing, cloud computing

Licenses, open source


What’s a front-end?
Basically, the user interface to the
parts of the system responsible for
“hot” computation

Internally, we speak of the itsme front-
end as the frame for the new
metaphor, proving support to
interaction (operations) and access to
applications


Front-ends
There exist many different metaphor
adopted by graphical (visual) front-
ends
- Yep, there are also non-visual: e.g., audio with
speech or gesture recognition, tactile interfaces
(Braille)


What does it take?
We considered and started from
‘desktop’ user interfaces, due to basic
similarities
Same elements used in a different way
- Still within the WIMP paradigm (“window, icon,
menu, pointing device”), at the moment
...so we can reuse existing stuff!
- Window management (well, almost)
- Basic system conﬁguration tools
- ...


Development
We have to redraw what’s on screen
- e.g., (ﬁle management) windows → venues, new
panels and widgets
and link elements according to
different policies
- e.g., drag and drop, elements behaviors (on click, ...)
Current prototype developed using:
- Sabayon Linux (4.*, now 5.*)
- Python
- QT


QT
Cross-platform toolkit to develop GUIs
Used by KDE, Google Earth, Skype
Owned by Nokia and distributed
according to LGPL
Uses C++ (but language bindings
available)

Alternatives we considered?
GTK+, and others

KDE http://www.kde.org/


GNOME http://www.gnome.org/


Enlightenment


But actually they are all the same old
desktop…


OLPC
One Laptop Per Child: cheap, low
consumption computers for education


OLPC → Sugar


Eldy
Linux distribution for elderly, but also
for people looking for a very simple
user interface
Italian initiative
Free
Supported by volunteers


Eldy


...and now let’s talk about itsme :-)

itsme: prototype v. 0.3

o !
s ee a de m
L e t ’s


Video of a previous version


Front-end architecture
The front-end follows a model/view/
state architecture
- The model classes store the data for the other
classes
- The view classes provide UI and most of the logic
(since they have to show the data and also
manage user interaction)
- The state classes implement a state machine
controlling the behavior of UI elements


The main distinction inside the FE is
between extensions and extendables.
The extendables package contains all
the classes which can be inherited to
create speciﬁc classes. The extensions
package contains all the speciﬁc
subclasses.


Open issues
Accessibility
- Do you see any possible problem?

What to make a default, what
cusomizable, what …?
- Can you ﬁnd examples?

Safety/security with respect to
applications
Blend with the Web

Why a back-end?
We need to store and manipulate
metadata for the things we see and
work with in the UI
Also data need to be stored and
accessed in a different way

...this problem is well known


Semantic Web
Huge amount of information on the
Web
HTML: syntax to describe structure
Meaning is not expressed
Computers can’t help users ﬁnding
and organizing stuff they don’t
“understand”


Example


The Web is made of documents...

apart from ﬁle extensions, they are all
the same and links have no meaning


...but we talk about different things

things are related one to another: how
can computers be aware of it?


Top-down solutions
Information analysis, web scraping,
natural language processing…

...unfeasible: human intervention, hard
to maintain, legal issues


Bottom-up solution
Embed semantical annotations into
the data
Beside describing the generical
structure of a document (HTML), add
some metadata describing what each
part of the structure is about

Example: not just links,
but links with a label

Let’s generalize
HTML “has evolved” to XML
Instead of only expressing hypertexts,
XML can be used to encode any form
of structured data
XML can be used to define more
specific languages (grammars, e.g.,
with DTDs)
XML can be used to define a way to
describe what is on the Web


RDF
Resource Description Framework
W3C standard for describing
resources in the Web
RDF identiﬁes things using
URIs(Uniform Resource Identiﬁers)
RDF uses simple statements (Triples)
to describe things:
- Thing-Property-Value
- Subject-Predicate-Object


What’s RDF like?

OK… but what does it mean?


RDF = graphs


Ontologies
How can computers know what labels
represent?
Interoperability is reached when
different parts share definitions
(vocabularies)
- syntactic vs semantic interoperability

If definitions are structured, and
relations are well defined as
properties, also further inference is
possible

Let’s make an example
Alice is a blogger who publishes
articles at http://example.com/alice
She wants to declare the license of
her work

The rel attribute specifies the
relationship between the current
document and the linked document.


She wants to specify title and creator
of an article
But there are no such attributes in
XHTML
She can use Dublin Core vocabulary
Namespace → interoperability


She wants to give Bob proper credit
when she posts his photos


She wants to display her name, email
and phone
She can use Friend-of-a-Friend
vocabulary


She wants to list her friends


Then what?
This was an example showing how to
express some metadata about what’s
been published

How can information be retrieved in a
smart way then?


SQL
Structured Query Language
Standard way to interact with
databases

E.g., SELECT * FROM ‘table’ WHERE
‘name’ LIKE ‘Marco’;

...but we have no tables, only graphs,
so this does not suit

SPARQL
SPARQL Protocol And RDF Query
Language
Used to manipulate RDF data
E.g., can be used to search for
“friends of Alice who created items
whose title contains ‘Bob’”


Semantic desktop
The Semantic Web vision can be
applied also to personal computing
Approach to deal with the contents of
documents – exploiting metadata
semantics


EU project for a Social Semantic
Desktop
Exploit ﬁles metadata for a different
interaction with things
Remind for later: The NEPOMUK/
OSCAF standards are taken up by
these projects and Nokia's Maemo
Platform


KDE/Nepomuk architecture


itsme back-end architecture
Application

Local / Network / DBus
File System
Generate notifications
Abstraction
for the front-end Interface Event
Notifier
Plugin Engine Direct
Access
Application
Virtual FS
Manager Get (serialized)
Email ... items and search
Send/receive email
plugin plugin metadata
Aggregate metadata in
Communication proxy
complete items
and File System
access for plugins
Search (to get) lists of Item Manager
items Log operations on
Search Update Time
Engine monitor Manager items
Dispatch updated items
Read/Write on
Logic

to plugin engine and
event notifier File System Distributed File
Metadata Manager Manager System
Metadata access, Metadata Soprano
extraction, storage Extractor Inference Refine Metadata

JStreams Virtuoso Index/Search
Extract Metadata from
RDF Metadata
files

Process specific file
types Storage

As in April 30th, now a little different...

Meta Tracker
RDF central storage for data and
metadata
- shared between applications
Miners to search and insert meta/data
- also on the Web
Extractors working with any type of
ﬁle
Nepomuk/KDE ontologies
SPARQL

Maemo


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