A. Appendix, Source Code of Email Tracer Application if __name__ == " __main__ " : startInterface ( argv = None

T. Amabile, The social psychology of creativity: A componential conceptualization., Journal of Personality and Social Psychology, vol.45, issue.2, pp.357-376, 1983.
DOI : 10.1037/0022-3514.45.2.357

C. Baldwin and K. Clark, Does code architecture mitigate free riding in the open source development model, Management Science, issue.7, p.52, 2006.

B. Behlendorf, Open source as a business strategy, Open Sources: Voices from the Open Source Revolution, pp.149-170, 1999.

S. Belenzon and M. A. Schankerman, Motivation and sorting in open source software innovation, 2008.

Y. Benkler, Coase's Penguin, or, Linux and "The Nature of the Firm", The Yale Law Journal, vol.112, issue.3, pp.367-445, 2002.
DOI : 10.2307/1562247

J. E. Bessen, Open Source Software: Free Provision Of Complex Public Goods, SSRN Electronic Journal, 2005.
DOI : 10.2139/ssrn.588763

J. E. Bessen and E. S. Maskin, Sequential innovation, patents, and imitation, 2000.
DOI : 10.1111/j.1756-2171.2009.00081.x

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.175.7986

J. Bitzer, Commercial versus open source software: the role of product heterogeneity in competition, Economic Systems, vol.28, issue.4, pp.369-381, 2004.
DOI : 10.1016/j.ecosys.2005.01.001

B. Boehm, Software engineering economics, 1981.

A. Bonaccorsi and C. Rossi, Contributing to the Common Pool Resources in Open Source Software. A Comparison Between Individuals and Firms, SSRN Electronic Journal, 2003.
DOI : 10.2139/ssrn.430920

A. Bonaccorsi and C. Rossi, Licensing Schemes in the Production and Distribution of Open Source Software: An Empirical Investigation, SSRN Electronic Journal, 2003.
DOI : 10.2139/ssrn.432641

A. Bonaccorsi and C. Rossi, Why Open Source software can succeed, Research Policy, vol.32, issue.7, pp.1243-1258, 2003.
DOI : 10.1016/S0048-7333(03)00051-9

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.13.4742

F. Brooks, The Mythical Man-Month: Essays on Software Engineering, 1978.

R. Casadesus-masanell and P. Ghemawat, Dynamic Mixed Duopoly: A Model Motivated by Linux vs. Windows, Management Science, vol.52, issue.7, pp.1072-1084, 2006.
DOI : 10.1287/mnsc.1060.0548

H. Chesbrough, Open Innovation: The New Imperative for Creating and Profiting from Technology, 2003.

L. Christensen and W. Greene, Economies of Scale in U.S. Electric Power Generation, Journal of Political Economy, vol.84, issue.4, Part 1, pp.655-676, 1976.
DOI : 10.1086/260470

R. Coase, The Lighthouse in Economics, The Journal of Law and Economics, vol.17, issue.2, pp.357-376, 1974.
DOI : 10.1086/466796

W. Cohen, R. Nelson, W. , and J. , Protecting their intellectual assets: Appropriability conditions and why US manufacturing firms patent (or not), 2000.
DOI : 10.3386/w7552

L. Dahlander, APPROPRIATION AND APPROPRIABILITY IN OPEN SOURCE SOFTWARE, International Journal of Innovation Management, vol.09, issue.03, pp.259-285, 2005.
DOI : 10.1142/S1363919605001265

L. Dahlander and M. Magnusson, Relationships between open source software companies and communities: Observations from Nordic firms, Research Policy, vol.34, issue.4, pp.481-493, 2005.
DOI : 10.1016/j.respol.2005.02.003

L. Dahlander and M. Wallin, A man on the inside: Unlocking communities as complementary assets, Research Policy, vol.35, issue.8, pp.1243-1259, 2006.
DOI : 10.1016/j.respol.2006.09.011

P. A. David and F. Rullani, Micro-dynamics of free and open source software development: Lurking, laboring and launching new projects on sourceforge, 2006.

N. Economides and E. Katsamakas, Two-Sided Competition of Proprietary vs. Open Source Technology Platforms and the Implications for the Software Industry, Management Science, vol.52, issue.7, pp.1057-1071, 2006.
DOI : 10.1287/mnsc.1060.0549

J. Eilhard, Loose contracts, tight control? Firms on SourceForge, 2008.

J. Eilhard, Open Source Incorporated, SSRN Electronic Journal, 2008.
DOI : 10.2139/ssrn.1360604

D. Evans and A. Layne-farrar, Software patents and open source: The battle over intellectual property rights, 2004.

C. Fershtman and N. Gandal, Microstructure of Collaboration: The Network of Open Source Software, SSRN Electronic Journal, 2008.
DOI : 10.2139/ssrn.1134342

A. Fosturi, M. Giarratana, and A. Luzzi, The Penguin Has Entered the Building: The Commercialization of Open Source Software Products, Organization Science, vol.19, issue.2, pp.292-328, 2008.
DOI : 10.1287/orsc.1070.0321

Y. Gao, M. Van-antwerp, S. Christley, and G. Madey, A research collaboratory for open source software research Available at: http://www, 2007.

. Gartner, Gartner says as number of business processes using open-source software increases, companies must adopt and enforce an oss policy, 2008.

R. Ghosh, R. Glott, B. Krieger, and B. Robles, Free/libre and open source software: Survey and study (floss), final report, Part 4: Survey of developers, 2002.

P. Giuri, M. Ploner, F. Rullani, and S. Torrisi, Skills, division of labor and performance in collective inventions: Evidence from open source software, International Journal of Industrial Organization, vol.28, issue.1, pp.54-68, 2010.
DOI : 10.1016/j.ijindorg.2009.07.004

Z. Griliches and J. Mairesse, Production Functions: The Search for Identification, pp.169-203, 1998.
DOI : 10.1017/CCOL521633230.006

S. Grossman and O. Hart, The Costs and Benefits of Ownership: A Theory of Vertical and Lateral Integration, Journal of Political Economy, vol.94, issue.4, pp.691-719, 1986.
DOI : 10.1086/261404

K. Haaland, S. K. Sowe, R. Ghosh, D. , and P. A. , Investigating the productivity of open source software developers, 2009.

J. Hammond, M. Gerush, and J. Silekis, Open source software goes mainstream, 2009.

J. Hausman, B. Hall, and Z. Griliches, Econometric Models for Count Data with an Application to the Patents-R & D Relationship, Econometrica, vol.52, issue.4, pp.909-938, 1984.
DOI : 10.2307/1911191

R. Hawkins, The economics of open source software for a competitive firm, NETNOMICS: Economic Research and Electronic Networking, vol.50, issue.2, pp.103-117, 2004.
DOI : 10.1007/s11066-004-2717-z

F. Hecker, Setting up shop: The business of open-source software, IEEE Software, vol.16, issue.1, pp.45-51, 1999.
DOI : 10.1109/52.744568

J. Heide and G. John, The Role of Dependence Balancing in Safeguarding Transaction-Specific Assets in Conventional Channels, Journal of Marketing, vol.52, issue.1, pp.20-35, 1988.
DOI : 10.2307/1251683

J. Henkel, Selective revealing in open innovation processes: The case of embedded Linux, Research Policy, vol.35, issue.7, pp.953-969, 2006.
DOI : 10.1016/j.respol.2006.04.010

J. Henkel, Champions of revealing -the role of open source developers in commercial firms, 2008.

J. Hennart, A transaction costs theory of equity joint ventures, Strategic Management Journal, vol.29, issue.4, pp.361-374, 1988.
DOI : 10.1002/smj.4250090406

J. Howison and K. Crowston, The perils and pitfalls of mining SourceForge, "International Workshop on Mining Software Repositories (MSR 2004)" W17S Workshop, 26th International Conference on Software Engineering, pp.7-11, 2004.
DOI : 10.1049/ic:20040467

A. Jaaksi, Building consumer products with open source Available at, 2006.

A. Jaaksi, How do we build maemo devices? Available at: http://jaaksi, 2009.

D. Jeon and S. Petriconi, Dynamics of knowledge-based service industry and open source, 2009.

L. Jeppesen and L. Frederiksen, Why do users contribute to firm-hosted user communities? Organization Science, pp.45-63, 2006.
DOI : 10.1287/orsc.1050.0156

P. Joskow, Vertical integration and long-term contracts: The case of coal-burning electric generating plants, Journal of Law Economics, and Organization, vol.1, issue.1, pp.33-80, 1985.

B. Klein, R. Crawford, and A. And-alchian, Vertical integration, appropriable rents, and the competitive contracting process, Journal of Law and Economics, pp.297-326, 1978.

G. Kroah-hartman, J. Corbet, and A. Mcpherson, Linux kernel development: How fast it is going, who is doing it, what they are doing, and who is sponsoring it (an august 2009 update) Linux Foundation, 2009.

K. Lakhani and R. Wolf, Why Hackers Do What They Do: Understanding Motivation and Effort in Free/Open Source Software Projects, Perspectives on Free and Open Source Software, chapter 1, pp.3-22, 2005.
DOI : 10.2139/ssrn.443040

R. Langois and G. Gazarelli, Of Hackers and Hairdressers: Modularity and the Organizational Economics of Open???source Collaboration, Industry and Innovation, vol.23, issue.2, pp.125-143, 2008.
DOI : 10.1016/0048-7333(87)90015-1

A. Laurent, Understanding open source and free software licensing, 2004.

J. Lerner, P. Pathak, and J. Tirole, The Dynamics of Open-Source Contributors, American Economic Review, vol.96, issue.2, pp.114-118, 2006.
DOI : 10.1257/000282806777211874

J. Lerner and J. Tirole, Some Simple Economics of Open Source, The Journal of Industrial Economics, vol.50, issue.2, pp.197-234, 2002.
DOI : 10.1111/1467-6451.00174

J. Lerner and J. Tirole, The Economics of Technology Sharing: Open Source and Beyond, Journal of Economic Perspectives, vol.19, issue.2, pp.99-120, 2005.
DOI : 10.1257/0895330054048678

F. Lévêque and Y. Ménière, Copyright versus patents: The open source software legal battle, 2006.

J. Marschak and W. Andrews, Random Simultaneous Equations and the Theory of Production, Econometrica, vol.12, issue.3/4, pp.143-172, 1944.
DOI : 10.2307/1905432

D. Mcgovan, Legal implications of open-source software, University of Illinois Law Review, vol.1, pp.241-304, 2001.

G. Muntz, The relation between science and practice and its bearing on the utility of the institute of metals, Journal of the Institute of Metals, vol.1, pp.289-291, 1909.

M. Mustonen, When Does a Firm Support Substitute Open Source Programming?, Journal of Economics <html_ent glyph="@amp;" ascii="&"/> Management Strategy, vol.42, issue.1, pp.121-139, 2005.
DOI : 10.1016/S0167-6245(01)00062-2

G. Olley and A. Pakes, The Dynamics of Productivity in the Telecommunications Equipment Industry, Econometrica, vol.64, issue.6, pp.1263-1297, 1996.
DOI : 10.2307/2171831

M. Olson, The Logic of Collective Action, 1971.

O. 'mahony, S. West, and J. , What makes a project open source? mitigating from organic to synthetic communities, 2005.

M. Osterloh and S. Rota, Open source software development-just another case of collective invention? Research Policy, pp.157-171, 2007.

L. Papke and J. Wooldridge, Econometric methods for fractional response variables with an application to 401 (k) plan participation rates, Journal of Applied Econometrics, pp.619-632, 1996.

B. Perens, The open source definition, Open Sources: Voices from the Open Source Revolution, chapter 12, pp.171-188, 1999.

B. Perens, The monster arrives: Software patents lawsuits against open source developers, 2006.

E. Raymond, The cathedral and the bazaar. Musings on Linux and Open Source by an accidental revolutionary, 2001.

L. Rosen, Which open source licens should I use for my software? available at, 2001.

L. Rosen, Open Source Licensing: Software Freedom and Intellectual Property Law, 2004.

K. Schmidt and M. Schnitzer, Public Subsidies for Open Source? Some Economic Policy Issues of the Software Market, SSRN Electronic Journal, 2003.
DOI : 10.2139/ssrn.319081

S. Scotchmer and S. Maurer, Open source software: The new intellectual property paradigm, Handbook of Economics and Information Systems, pp.285-319, 2006.

S. Shah, Sources and patterns of innovation in a consumer products field: Innovations in sporting equipment. Sloan School of Management, Massachusetts Institute of Technology, p.4105, 2000.

S. Shah, Motivation, Governance, and the Viability of Hybrid Forms in Open Source Software Development, Management Science, vol.52, issue.7, pp.1000-1014, 2006.
DOI : 10.1287/mnsc.1060.0553

H. Shelanski and P. Klein, Empirical research in transaction cost economics: a review and assessment, Journal of Law Economics, and Organization, vol.11, issue.2, pp.335-361, 1995.

P. V. Singh, Y. Tan, and V. Mookerjee, Network Effects: The Influence of Structural Social Capital on Open Source Project Success, SSRN Electronic Journal, 2008.
DOI : 10.2139/ssrn.1111868

V. Valloppillil, Halloween documents. Internal Strategy Microsoft Memorandum, 1998.

K. Ven and H. Mannaert, Challenges and strategies in the use of open source software by independent software vendors. Information and Software Technology, pp.991-1002, 2007.

M. Välimäki, Dual licensing in open source software industry. Systemes d'Information et Management, 2003.

E. Von-hippel, The Sources of Innovation, 1988.
DOI : 10.1007/978-3-8349-9320-5_10

E. Von-hippel, Innovation by user communities: Learning from open-source software. (cover story), MIT Sloan Management Review, vol.42, issue.4, pp.82-86, 2001.

E. Von-hippel and R. Katz, Shifting Innovation to Users via Toolkits, Management Science, vol.48, issue.7, pp.821-833, 2002.
DOI : 10.1287/mnsc.48.7.821.2817

E. Von-hippel, V. Krogh, and G. , Open Source Software and the ???Private-Collective??? Innovation Model: Issues for Organization Science, Organization Science, vol.14, issue.2, pp.209-223, 2003.
DOI : 10.1287/orsc.14.2.209.14992

G. Von-krogh, S. Spaeth, and K. R. Lakhani, Community, Joining, and Specialization in Open Source Software Innovation: A Case Study, SSRN Electronic Journal, issue.7, pp.321217-1241, 2003.
DOI : 10.2139/ssrn.387500

A. Weiss, Real world open source: The TCO question. Serverwatch. available at, 2005.

J. West, How open is open enough?, Research Policy, vol.32, issue.7, pp.1259-1285, 2003.
DOI : 10.1016/S0048-7333(03)00052-0

D. Wheeler, More than a gigabuck: Estimating gnu/linux's size. available from, 2002.

T. Wichmann, Free/libre and open source software: Survey and study (floss), final report, part I: Use of open source software in firms and public institutions, 2002.

T. Wichmann, Free/libre and open source software: Survey and study (floss), final report, part II: Firms' open source activities-motivations and policy implications, 2002.

O. Bibliography-williamson, Hierarchical Control and Optimum Firm Size, Journal of Political Economy, vol.75, issue.2, pp.123-138, 1967.
DOI : 10.1086/259258

O. Williamson, Comparative economic organization: The analysis of discrete structural alternatives Administrative science quarterly, pp.219-263, 1991.

O. Williamson, Economics and Organization: A Primer, California Management Review, vol.19, issue.2, pp.131-146, 1996.
DOI : 10.1016/0048-7333(86)90027-2