KEMBAR78
FLOSS development | PDF
FLOSS
Development
Prof. dr. Frederik Questier - Vrije Universiteit Brussel
Presented at University of Hasselt 11/08/2018 for the
“Workshop interoperability between information platforms”
This presentation can be found at
http://questier.com
http://www.slideshare.net/Frederik_Questier
Werken met portfolio's
04/10/05 | pag. 4
5
FLOSS user since 90's / FLOSS-only since 2003
Co-founder, former Research & Innovation Director of Chamilo
6
My previous FLOSS workshops
in Cuba and Ethiopia included:
➢ FLOSS: what and why?
➢ FLOSS experiences worldwide
➢ FLOSS tools for Academics
➢ Strategies for institutional FLOSS migrations
See https://www.slideshare.net/Frederik_Questier
7
Focus of this workshop
Development in FLOSS environments
End assignment
after this session
Inspired by the FLOSS development styles,
what do you recommend
to improve the development of your projects?
Assignments and answers page:
http://shorturl.at/dkmyM
https://docs.google.com/document/d/1LPbeZALW5Yv071_tUvpVQHo-lsT60G37dp8HoirD6_w/edit#
9
PART I
Short rehearsal:
Free Libre Open Source Software:
What (& Why)?
Early software days
➢ In the 1950s and into the 1960s almost all software
was produced by computer science academics and
corporate researchers working in collaboration.
➢ Source code was generally distributed with the
software
➢ IBM “SHARE” user group
➢ Digital Equipment Computer Users' Society
(DECUS)
Source code: if encrypt(password) == encryptedpassword, then login=1, end
Compiled code: 00100101110101001100110000111101100011000111000110101
Open Letter to
Hobbyists:
“Your sharing is
stealing”
Bill Gates, 1976
Monopoly abuse
US justice department 1999:
“Microsoft is a monopolist and
it engaged in massive
anticompetitive practices
that harmed innovation
and limited consumer choice”
13
"The most fundamental
way of helping other
people,
is to teach people
how to do things better
or how to better their
lives.
For people
who use computers,
this means sharing
the recipes
you use on your
computer,
in other words
the programs you run."
14
1980's: Stallman defined
“Free Software”
The freedom to
➢ use
➢ study
➢ distribute
➢ improve
the program
1998: “Open Source” sounds
better than “Free Software”?
16
The software Freedoms
require access to the source code
→
“Open Source Software” (OSS)
Free Open Source Software (FOSS)
Free Libre Open Source Software (FLOSS)
Software categories
➢ Anti-features are features that users don’t want, including:
➢ Copy-protection
➢ DRM = Digital Rights/Restrictions Management
➢ Data lock-in because of secret file formats
➢ Time-limit / Planned obsolescence
➢ Artificial limitations (e.g. limited RAM, HD and max 3 concurrent programs in MS Windows Vista Home)
➢ Advertisements
➢ Tracking / Spyware
Free Software Licenses
➢ The freedoms are guaranteed and enforced by licenses, e.g.
➢ GNU GPL (General Public License)
➢ The 4 freedoms + copyleft (share alike)
➢ if binary offered, source code must be offered too
➢ (on request, at low cost)
➢ must stay GPL.
➢ BSD (Berkeley Software Distribution)
➢ Attribution
➢ No copyleft requirements for distribution
➢ BSD code often in closed source software (MS, Mac, ...)
➢ Apple Public Source License v2
Assignment
➢ Search and report the licence of your
software:
➢ ABCD v2
➢ ABCD v3
➢ EsFacil
➢ Moodle
➢ Vivo
➢ Dspace
Are FLOSS licenses eternal?
➢ Yes
➢ But… newer software versions could be released
under different license if all copyright holders agree.
➢ Could happen if the copyright holder is a company
➢ Very unlikely to happen (in a bad way) if copyright is
assigned to a foundation with FLOSS values or to many
individual developers.
➢ Users can continue to use old FLOSS versions
➢ Developers can fork and continue the development of
the FLOSS version
Always check the license
➢ Avoid a Mendeley scenario...
➢ Starting with open promises
➢ Try to get free developers
➢ Sold out to Elsevier
➢ Now user-hostile:
1991 comp sci
student
Usenet posting to the
newsgroup
"comp.os.minix.":
“I'm doing a (free)
operating system (just a
hobby, won't be big and
professional like gnu) for
386(486) AT clones.”
13594 developers from >1300 companies
have contributed to Linux kernel
25
Linus Torvalds
“Making Linux GPL'd
was definitely
the best thing I ever did.”
26
“Open Source ... it's just a
superior way of working together
and generating code.”
“Like science, Open Source
allows people to build on a solid
base of previous knowledge,
without some silly hiding.”
“you can obviously never do as
well in a closed environment as
you can with open scientific
methods.”
Linus Torvalds (2007-03-19). The Torvalds
Transcript: Why I 'Absolutely Love' GPL Version 2.
"Congratulations, you're on the winning team.
Linux has crossed the chasm to mainstream adoption."
➢ Jeffrey Hammond, principal analyst at Forrester Research, LinuxCon, 2010
“Linux has come to dominate almost every category of
computing, with the exception of the desktop”
➢ Jim Zemlin, Linux Foundation Executive Director, 2011
“Linux is the benchmark of Quality”
➢ Coverity Report 2012
100% of top 500 supercomputers run Linux
Android, a mobile version of Linux,
has overall largest market share
Android
Regional example: Extremadura
➢ poorly developed region → economic revival
➢ based on FLOSS (customized GNU/LinEx)
➢ computer access for every student
➢ saved >18M € on initial 80,000 school computers
➢ total software cost: 1.08 Euro/PC/year
➢ bigger project
➢ stimuli for companies, centres for citizens
➢ economic revival -> European regional innovation award
Don't use personal operating systems
in multi-user environments
Esperenza Computer Classroom with software sponsored by Microsoft
1 computer per user?
One (library catalog) computer per user?
37
Free yourselfFree yourself
from dogmas!from dogmas!
(K12)LTSP
Linux Terminal Server Project
Networked classrooms
Fat server
runs the applications
Thin clients
visualize the applications
need no hard disk
can be 15 years old PC's
Drupal meeting
Antwerp 2005
Drupalcon DC 2009
Drupal
Content Management Platform
➢ Powers 2% of websites
➢ USA White House, MTV UK, Sony Music, Al Jazeera, ...
➢ >2500 themes
➢ >39500 modules
➢ >37000 developers
➢ >1.3M members
➢ 2M/month unique visitors on drupal.org
➢ Commercial Open Source company
➢ Founded 2007
➢ $118.5 million venture capital
➢ 3800 enterprise customers
➢ 500 employees
➢ Fastest Growing Private Technology Company in
North America, 2013
47
My personal experience
48
1998: how it started
➢ In a Belgian University
➢ many people were frustrated
by the inflexible, non-free elearning systems
they had to use
➢ Prof. dr. Thomas Depraetere
➢ starts the Claroline e-learning platform
➢ publishes it as Free Software
➢ got grants for it
49
2004: fork 1
original author wants to break free
➢ Growing number of users
➢ outside the university
➢ requesting professional services
➢ Prof. dr. Thomas Depraetere
➢ starts a company, Dokeos
➢ can't call it Claroline, cause university has trademark
➢ can reuse software code, as it is Free !!!
50
2010: fork 2
the community wants to break free
51
Automated Chamilo analysis
by Ohloh.net
52
53
54
55
Version Control
FLOSS devs, geo-distributed as they are,
needed and developed some powerful
collaboration dev tools:
➢ Concurrent Versions System (CVS)
➢ Subversion revision control system (SVN)
➢ Git
Assignment
➢ Search the source code repository for:
➢ ABCD v2
➢ ABCD v3
➢ EsFacil
➢ Moodle
➢ Vivo
➢ Dspace
57
Communication
➢ IRC
➢ Mailing lists
➢ Websites
➢ Wikis
Assignment
➢ How are the DEVELOPERS of these
projects communicating:
➢ ABCD v2
➢ ABCD v3
➢ EsFacil
➢ Moodle
➢ Vivo
➢ Dspace
Bug tracking
➢ Bugzilla
➢ Redmine
➢ Trac
Assignment
➢ How are these projects tracking bugs and
feature requests:
➢ ABCD v2
➢ ABCD v3
➢ EsFacil
➢ Moodle
➢ Vivo
➢ Dspace
61
Success in FLOSS requires you to serve
➢ those who spend time to save money
➢ those who spend money to save time
-- Mårten Mickos, CEO MySQL
Software freedom allows you to tap into
innovation power and network effects
otherwise not available
Mårten Mickos, CEO MySQL
“Companies should work with Open Source
for the value of the ecosystem and community,
not just the value of the code”
Eric Brewer, Google vice-president of infrastructure, 2017
Werken met portfolio's
04/10/05 | pag. 64
Build and Manage
a Community?
65
Development
Linus Torvalds' style
Release early and often
Delegate everything you can
Be open to the point of promiscuity
Linus' Law
"given enough eyeballs,
all bugs are shallow."
66
Book published under
Open Publication License
19 lessons for open source
development
Commercial development
= Cathedral style
Open Source development
= Bazaar style
67
68
69
The Cathedral and the Bazaar
about developers
1. Every good work of software
starts by scratching a developer's personal itch.
2. Good programmers know what to write.
Great ones know what to rewrite (and reuse).
70
The Cathedral and the Bazaar
about users
6. Treating your users as co-developers is your least-hassle
route to rapid code improvement and effective debugging.
7. Release early. Release often. And listen to your customers.
8. Given a large enough beta-tester and co-developer base,
almost every problem will be characterized quickly
and the fix obvious to someone.
11. The next best thing to having good ideas is
recognizing good ideas from your users.
Sometimes the latter is better.
71
The Cathedral and the Bazaar
about development
17. A security system is only as secure as its secret.
Beware of pseudo-secrets.
18. To solve an interesting problem,
start by finding a problem that is interesting to you.
19. Provided the development coordinator
has a medium at least as good as the Internet,
and knows how to lead without coercion,
many heads are inevitably better than one.
72
Assignment
➢ Search all 19 lessons from Cathedral and
the Bazaar (e.g. Wikipedia)
➢ Search the book
➢ What’s your favourite lesson? Why?
73
Good programmers know what to write.
Great ones know what to rewrite (and reuse)
➢ Assignment:
➢ Search all pairs:
➢ ABCD - Moodle
➢ ABCD - Vivo
➢ ABCD - Dspace
➢ Moodle - Vivo
➢ Moodle - Dspace
➢ Vivo - Dspace
➢ Do you find any existing features, add-ons,
plugins, protocols, … connecting these pairs?
74
Is ABCD 3
welcoming to
new developers and users?
75
Teach / involve students in
FLOSS communities
PhD research Dayana Tejera (UCI)
76
Are you member of the community?
How will you get your contribution accepted?
Respect and follow community coding style!
Recommended best practices from the open source development model
From: Ibrahim Haddad, The Open Source Development Model:
Overview, Benefits and Recommendations
http://aaaea.org/Al-muhandes/2008/February/open_src_dev_model.htm
End assignment
Inspired by the FLOSS development styles,
what do you recommend
to improve the development of your projects?
Assignments and answers page:
http://shorturl.at/dkmyM
https://docs.google.com/document/d/1LPbeZALW5Yv071_tUvpVQHo-lsT60G37dp8HoirD6_w/edit#
79
DAREDARE
TO SHARETO SHARE
Credits
➢
Photo Linus Torvalds: GFDL. Permission of Martin Streicher, Editor-in-Chief,
LINUXMAG.com
➢ Picture (open source business strategies) from IT Manager's Journal, may 2004,
with personal permission from John Koenig
➢ Screenshot http://www.openhandsetalliance.com/
➢
Cartoon Open Source Fish by openssoft
➢ T-Shirt “Best things are life are free” by http://zazzle.com
➢ Drupalcon DC 2009 copyright by “Chris” (Flickr)
➢ Screenshot Acquia
➢
Internet map by The Opte Project, CC-by
➢ Open arrow, CC-by-nd by ChuckCoker
➢ Share matches CC-by-nc-nd by Josh Harper
➢ Question mark CC-by by Stefan Baudy
➢ Social Icons by Iconshock http://www.iconshock.com/social-icons/
This presentation was made with 100% Free Software
No animals were harmed
Questier.com
Frederik AT Questier.com
www.linkedin.com/in/fquestie
www.diigo.com/user/frederikquestier
www.slideshare.net/Frederik_Questier
Q
uestions?
Gracias
A
m
eseginalehu!

FLOSS development

  • 1.
    FLOSS Development Prof. dr. FrederikQuestier - Vrije Universiteit Brussel Presented at University of Hasselt 11/08/2018 for the “Workshop interoperability between information platforms”
  • 2.
    This presentation canbe found at http://questier.com http://www.slideshare.net/Frederik_Questier
  • 3.
  • 4.
    5 FLOSS user since90's / FLOSS-only since 2003 Co-founder, former Research & Innovation Director of Chamilo
  • 5.
    6 My previous FLOSSworkshops in Cuba and Ethiopia included: ➢ FLOSS: what and why? ➢ FLOSS experiences worldwide ➢ FLOSS tools for Academics ➢ Strategies for institutional FLOSS migrations See https://www.slideshare.net/Frederik_Questier
  • 6.
    7 Focus of thisworkshop Development in FLOSS environments
  • 7.
    End assignment after thissession Inspired by the FLOSS development styles, what do you recommend to improve the development of your projects? Assignments and answers page: http://shorturl.at/dkmyM https://docs.google.com/document/d/1LPbeZALW5Yv071_tUvpVQHo-lsT60G37dp8HoirD6_w/edit#
  • 8.
    9 PART I Short rehearsal: FreeLibre Open Source Software: What (& Why)?
  • 9.
    Early software days ➢In the 1950s and into the 1960s almost all software was produced by computer science academics and corporate researchers working in collaboration. ➢ Source code was generally distributed with the software ➢ IBM “SHARE” user group ➢ Digital Equipment Computer Users' Society (DECUS) Source code: if encrypt(password) == encryptedpassword, then login=1, end Compiled code: 00100101110101001100110000111101100011000111000110101
  • 10.
    Open Letter to Hobbyists: “Yoursharing is stealing” Bill Gates, 1976
  • 11.
    Monopoly abuse US justicedepartment 1999: “Microsoft is a monopolist and it engaged in massive anticompetitive practices that harmed innovation and limited consumer choice”
  • 12.
    13 "The most fundamental wayof helping other people, is to teach people how to do things better or how to better their lives. For people who use computers, this means sharing the recipes you use on your computer, in other words the programs you run."
  • 13.
    14 1980's: Stallman defined “FreeSoftware” The freedom to ➢ use ➢ study ➢ distribute ➢ improve the program
  • 14.
    1998: “Open Source”sounds better than “Free Software”?
  • 15.
    16 The software Freedoms requireaccess to the source code → “Open Source Software” (OSS) Free Open Source Software (FOSS) Free Libre Open Source Software (FLOSS)
  • 16.
    Software categories ➢ Anti-featuresare features that users don’t want, including: ➢ Copy-protection ➢ DRM = Digital Rights/Restrictions Management ➢ Data lock-in because of secret file formats ➢ Time-limit / Planned obsolescence ➢ Artificial limitations (e.g. limited RAM, HD and max 3 concurrent programs in MS Windows Vista Home) ➢ Advertisements ➢ Tracking / Spyware
  • 17.
    Free Software Licenses ➢The freedoms are guaranteed and enforced by licenses, e.g. ➢ GNU GPL (General Public License) ➢ The 4 freedoms + copyleft (share alike) ➢ if binary offered, source code must be offered too ➢ (on request, at low cost) ➢ must stay GPL. ➢ BSD (Berkeley Software Distribution) ➢ Attribution ➢ No copyleft requirements for distribution ➢ BSD code often in closed source software (MS, Mac, ...) ➢ Apple Public Source License v2
  • 18.
    Assignment ➢ Search andreport the licence of your software: ➢ ABCD v2 ➢ ABCD v3 ➢ EsFacil ➢ Moodle ➢ Vivo ➢ Dspace
  • 19.
    Are FLOSS licenseseternal? ➢ Yes ➢ But… newer software versions could be released under different license if all copyright holders agree. ➢ Could happen if the copyright holder is a company ➢ Very unlikely to happen (in a bad way) if copyright is assigned to a foundation with FLOSS values or to many individual developers. ➢ Users can continue to use old FLOSS versions ➢ Developers can fork and continue the development of the FLOSS version
  • 20.
    Always check thelicense ➢ Avoid a Mendeley scenario... ➢ Starting with open promises ➢ Try to get free developers ➢ Sold out to Elsevier ➢ Now user-hostile:
  • 22.
    1991 comp sci student Usenetposting to the newsgroup "comp.os.minix.": “I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones.”
  • 23.
    13594 developers from>1300 companies have contributed to Linux kernel
  • 24.
    25 Linus Torvalds “Making LinuxGPL'd was definitely the best thing I ever did.”
  • 25.
    26 “Open Source ...it's just a superior way of working together and generating code.” “Like science, Open Source allows people to build on a solid base of previous knowledge, without some silly hiding.” “you can obviously never do as well in a closed environment as you can with open scientific methods.” Linus Torvalds (2007-03-19). The Torvalds Transcript: Why I 'Absolutely Love' GPL Version 2.
  • 26.
    "Congratulations, you're onthe winning team. Linux has crossed the chasm to mainstream adoption." ➢ Jeffrey Hammond, principal analyst at Forrester Research, LinuxCon, 2010 “Linux has come to dominate almost every category of computing, with the exception of the desktop” ➢ Jim Zemlin, Linux Foundation Executive Director, 2011 “Linux is the benchmark of Quality” ➢ Coverity Report 2012
  • 27.
    100% of top500 supercomputers run Linux
  • 28.
    Android, a mobileversion of Linux, has overall largest market share
  • 29.
  • 32.
    Regional example: Extremadura ➢poorly developed region → economic revival ➢ based on FLOSS (customized GNU/LinEx) ➢ computer access for every student ➢ saved >18M € on initial 80,000 school computers ➢ total software cost: 1.08 Euro/PC/year ➢ bigger project ➢ stimuli for companies, centres for citizens ➢ economic revival -> European regional innovation award
  • 33.
    Don't use personaloperating systems in multi-user environments
  • 34.
    Esperenza Computer Classroomwith software sponsored by Microsoft 1 computer per user?
  • 35.
    One (library catalog)computer per user?
  • 36.
  • 38.
    (K12)LTSP Linux Terminal ServerProject Networked classrooms Fat server runs the applications Thin clients visualize the applications need no hard disk can be 15 years old PC's
  • 40.
  • 41.
  • 42.
    Drupal Content Management Platform ➢Powers 2% of websites ➢ USA White House, MTV UK, Sony Music, Al Jazeera, ... ➢ >2500 themes ➢ >39500 modules ➢ >37000 developers ➢ >1.3M members ➢ 2M/month unique visitors on drupal.org
  • 44.
    ➢ Commercial OpenSource company ➢ Founded 2007 ➢ $118.5 million venture capital ➢ 3800 enterprise customers ➢ 500 employees ➢ Fastest Growing Private Technology Company in North America, 2013
  • 46.
  • 47.
    48 1998: how itstarted ➢ In a Belgian University ➢ many people were frustrated by the inflexible, non-free elearning systems they had to use ➢ Prof. dr. Thomas Depraetere ➢ starts the Claroline e-learning platform ➢ publishes it as Free Software ➢ got grants for it
  • 48.
    49 2004: fork 1 originalauthor wants to break free ➢ Growing number of users ➢ outside the university ➢ requesting professional services ➢ Prof. dr. Thomas Depraetere ➢ starts a company, Dokeos ➢ can't call it Claroline, cause university has trademark ➢ can reuse software code, as it is Free !!!
  • 49.
    50 2010: fork 2 thecommunity wants to break free
  • 50.
  • 51.
  • 52.
  • 53.
  • 54.
    55 Version Control FLOSS devs,geo-distributed as they are, needed and developed some powerful collaboration dev tools: ➢ Concurrent Versions System (CVS) ➢ Subversion revision control system (SVN) ➢ Git
  • 55.
    Assignment ➢ Search thesource code repository for: ➢ ABCD v2 ➢ ABCD v3 ➢ EsFacil ➢ Moodle ➢ Vivo ➢ Dspace
  • 56.
    57 Communication ➢ IRC ➢ Mailinglists ➢ Websites ➢ Wikis
  • 57.
    Assignment ➢ How arethe DEVELOPERS of these projects communicating: ➢ ABCD v2 ➢ ABCD v3 ➢ EsFacil ➢ Moodle ➢ Vivo ➢ Dspace
  • 58.
  • 59.
    Assignment ➢ How arethese projects tracking bugs and feature requests: ➢ ABCD v2 ➢ ABCD v3 ➢ EsFacil ➢ Moodle ➢ Vivo ➢ Dspace
  • 60.
    61 Success in FLOSSrequires you to serve ➢ those who spend time to save money ➢ those who spend money to save time -- Mårten Mickos, CEO MySQL
  • 61.
    Software freedom allowsyou to tap into innovation power and network effects otherwise not available Mårten Mickos, CEO MySQL
  • 62.
    “Companies should workwith Open Source for the value of the ecosystem and community, not just the value of the code” Eric Brewer, Google vice-president of infrastructure, 2017
  • 63.
    Werken met portfolio's 04/10/05| pag. 64 Build and Manage a Community?
  • 64.
    65 Development Linus Torvalds' style Releaseearly and often Delegate everything you can Be open to the point of promiscuity Linus' Law "given enough eyeballs, all bugs are shallow."
  • 65.
    66 Book published under OpenPublication License 19 lessons for open source development Commercial development = Cathedral style Open Source development = Bazaar style
  • 66.
  • 67.
  • 68.
    69 The Cathedral andthe Bazaar about developers 1. Every good work of software starts by scratching a developer's personal itch. 2. Good programmers know what to write. Great ones know what to rewrite (and reuse).
  • 69.
    70 The Cathedral andthe Bazaar about users 6. Treating your users as co-developers is your least-hassle route to rapid code improvement and effective debugging. 7. Release early. Release often. And listen to your customers. 8. Given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix obvious to someone. 11. The next best thing to having good ideas is recognizing good ideas from your users. Sometimes the latter is better.
  • 70.
    71 The Cathedral andthe Bazaar about development 17. A security system is only as secure as its secret. Beware of pseudo-secrets. 18. To solve an interesting problem, start by finding a problem that is interesting to you. 19. Provided the development coordinator has a medium at least as good as the Internet, and knows how to lead without coercion, many heads are inevitably better than one.
  • 71.
    72 Assignment ➢ Search all19 lessons from Cathedral and the Bazaar (e.g. Wikipedia) ➢ Search the book ➢ What’s your favourite lesson? Why?
  • 72.
    73 Good programmers knowwhat to write. Great ones know what to rewrite (and reuse) ➢ Assignment: ➢ Search all pairs: ➢ ABCD - Moodle ➢ ABCD - Vivo ➢ ABCD - Dspace ➢ Moodle - Vivo ➢ Moodle - Dspace ➢ Vivo - Dspace ➢ Do you find any existing features, add-ons, plugins, protocols, … connecting these pairs?
  • 73.
    74 Is ABCD 3 welcomingto new developers and users?
  • 74.
    75 Teach / involvestudents in FLOSS communities PhD research Dayana Tejera (UCI)
  • 75.
    76 Are you memberof the community? How will you get your contribution accepted? Respect and follow community coding style!
  • 76.
    Recommended best practicesfrom the open source development model From: Ibrahim Haddad, The Open Source Development Model: Overview, Benefits and Recommendations http://aaaea.org/Al-muhandes/2008/February/open_src_dev_model.htm
  • 77.
    End assignment Inspired bythe FLOSS development styles, what do you recommend to improve the development of your projects? Assignments and answers page: http://shorturl.at/dkmyM https://docs.google.com/document/d/1LPbeZALW5Yv071_tUvpVQHo-lsT60G37dp8HoirD6_w/edit#
  • 78.
  • 79.
    Credits ➢ Photo Linus Torvalds:GFDL. Permission of Martin Streicher, Editor-in-Chief, LINUXMAG.com ➢ Picture (open source business strategies) from IT Manager's Journal, may 2004, with personal permission from John Koenig ➢ Screenshot http://www.openhandsetalliance.com/ ➢ Cartoon Open Source Fish by openssoft ➢ T-Shirt “Best things are life are free” by http://zazzle.com ➢ Drupalcon DC 2009 copyright by “Chris” (Flickr) ➢ Screenshot Acquia ➢ Internet map by The Opte Project, CC-by ➢ Open arrow, CC-by-nd by ChuckCoker ➢ Share matches CC-by-nc-nd by Josh Harper ➢ Question mark CC-by by Stefan Baudy ➢ Social Icons by Iconshock http://www.iconshock.com/social-icons/
  • 80.
    This presentation wasmade with 100% Free Software No animals were harmed Questier.com Frederik AT Questier.com www.linkedin.com/in/fquestie www.diigo.com/user/frederikquestier www.slideshare.net/Frederik_Questier Q uestions? Gracias A m eseginalehu!