Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
Core Developers for an Award Winning Open Source Content
Management System: Profile Analysis
Zhengzhong Shi
This paper is to answer one question: who are the core
developers for Drupal, an award winning content management
system wildly used as a platform to develop e-commerce and ebusiness web systems. Profile data of the core developers are
collected from Drupal’s community site drupal.org. Descriptive
statistics are presented and ANOVA is used to test the
differences between male and female core developers. It is
found that male developers are still the dominant force in
Drupal core development. No statistically significant differences
are found between female and male core developers except
that female core developers on average contribute more to the
Drupal core. Further, multi-role playing is also compared
between male and female core developers and again no
statistically significant differences are identified.
JEL Codes: Management - E-Commerce and E-Business
1. Introduction
“Drupal is an open source content management platform powering millions of websites
and applications. It’s built, used, and supported by an active and diverse community of
people around the world” (Drupal.org). In essence, Drupal is a Web-based content
management system (CMS) based on which web systems can be developed to enable
e-commerce and e-business.
At this time of writing (April 24, 2013), based on the data from Drupal.org, there are
957199 people in 228 countries speaking 181 languages power Drupal. Among those
people who are involved in Drupal development, there are populations such as module
developers (25,370 at the time of writing), themers, site developers, educators, clients
and etc. These populations form the eco-system of the Drupal community.
In particular, there are 90 core developers besides 1 founder. These core developers
working with the founder are responsible for designing the overall architecture and have
the authority to make decisions on whether a contributed module (i.e., the extended
functionality of the Drupal platform) can be added to the core. Drupal core developers
are critical to the evolution of the Drupal platform. This paper is to analyze the publicly
available profile data of these core developers to understand who these developers are.
2. Literature Review
Open source software (OSS) and related communities have been a hot research area
for the past decade. Numerous studies focused on individual level motivation and
participation in OSS development (Roberts, Hann, and Slaughter, 2006; Fang and

Zhengzhong Shi, University of Massachusetts at Dartmouth, MA, USA, email: zshi@umassd.edu
1
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
Neufeld, 2009; Wu, Gerlach, and Young 2007; Hahn, Moon, and Zhang, 2008; Li, Tan,
and Teo, 2012). In addition, commercial companies were also found to contribute to the
OSS development (Andersen-Gott, Ghinea, and Bygstad, 2012). Further, factors
impacting OSS project success have also been explored. For example, Stewart and
Gosain (2006) investigated how OSS community values, norms, and beliefs influence
OSS project effectiveness in terms of attracting and retaining team members and
guiding project development towards success. This current paper is to follow these lines
of thinking and to identify who are the core developers for Drupal through profile data
collection and analysis with the goal of laying the foundation for future research on why
as an OSS Drupal is such a successful story to ultimately advance our knowledge of
OSS success factors.
3. The Methodology
Evolution of Drupal: Dries Buytaert is the founder of Drupal and he has 21486 commits
to Drupal core (11062 commits) and other 134 modules by the time profile data
collection was completed. In his blog (http://buytaert.net/), he describes himself as “the
original creator and project lead of Drupal, an open source social publishing system. He
is co-founder and chief technology officer of Acquia, a venture-backed software
company that offers products and services for Drupal.” Until this time to writing, Drupal
has seven stable major core releases and Drupal 8 is actively under development.
Figure 1 demonstrates the evolution of 5 major releases (data are available only for
Drupal, 4, 5, 6, 7 and 8). The numbers on the vertical axis are used to represent
different major and minor releases with higher level releases having a larger number.
Appendix A has all the detailed data on all major and minor releases since Drupal 4.7.
Data Collection: Drupal community site (drupal.org) is used as the source to collect
profile data for those Drupal core developers. All the profile data can be accessed at
http://drupal.org/node/3060/committers. Since these developers continuously make
commits to the core and we can only take a snapshot of their profiles. Profile data were
collected within one day in April 2013. Profile data include responses to the questions
listed in Table 1. Information such as name, gender, country of citizenship, and other
bio information may also be provided by these developers.
2
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
Table 1: Profile Questions on Drupal.org
1. I contributed Drupal patches
2. I contributed Drupal modules
3. I contributed Drupal themes
4. I contributed Drupal installation profiles
5. I contributed to Drupal issue
queues
6. I contributed Drupal documentation
7. I contributed Drupal translations
8. I contributed Drupal automated tests
9. I reviewed Project applications
10. I help in the Drupal support forums
11. I provide Drupal-related services
12. I give support on IRC
13. I help mentor new contributors
14. Conferences attended
Data Analysis and Results: Table 2 lists countries from which Drupal core developers
are coming. US has 31 members (34.4%) and Germany and UK have 8 (8.9%) and
7(7.8%) respectively. Belgium and Canada have 6 (6.7%) developers each. Clearly,
core developers are mostly from developed countries. Table 3 lists gender distribution
and it is found that male developers (71, 78.9%) are still the dominant force among core
developers. However, one female member (webchick http://drupal.org/user/24967,
http://www.webchick.net/) plays a major role in Drupal development. She is the comaintainer for Drupal core. She has 4616 commits to Drupal core and 8274 commits in
total and covers 79 modules besides Drupal core.
Table 2: Country Distribution of Drupal Core Developers
Country
Number of Contributors
Percentage
US
31
34.4%
Germany
8
8.9%
UK
7
7.8%
Belgium
6
6.7%
Canada
6
6.7%
France
4
4.4%
Spain
4
4.4%
Russian Fed
3
3.3%
Unspecified
3
3.3%
Hungary
2
2.2%
Sweden
2
2.2%
Switzerland
2
2.2%
Argentina, Australia, Austria, Costa Rica, Denmark, Hungary, Japan, Mexico,
Netherlands, Norway, Romania, Serbia, and Slovenia have 1 member involved in
Drupal core development. (Founder is not included)
Total
90
100%
Note: There are 44 (48.9%) contributors who are members of Drupal Association.
3
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
Table 3: Gender Distribution
Number of
Gender
Contributors
Female
7
Male
71
Unspecified
12
Total
90
Percentage
7.8%
78.9%
13.3%
100%
Table 4: Descriptive Statistics of Male and Female Core Developers
Number of Weeks
Commits
Total
Projects
Gender
since Registering with
to Core Commits Covered
Drupal Community Site
312.1
743.0
1571.4
30.0
Mean
7.0
7.0
7.0
7.0
N
Female
Std.
67.7
1707.6
2966.6
24.1
Deviation
300.2
92.5
1010.1
34.2
Mean
71.0
71.0
71.0
71.0
N
Male
Std.
124.7
289.9
1508.5
31.4
Deviation
301.3
150.8
1060.5
33.8
Mean
Total
N
Std.
Deviation
78.0
78.0
78.0
78.0
120.4
581.9
1667.5
30.7
Table 5: Comparison between Male and Female Core Developers
weeks * Gender Between Groups
Commits to
Core * Gender
Total Commits
* Gender
Projects
Covered *
Gender
Within Groups
Total
Between Groups
Within Groups
Total
Between Groups
Within Groups
Total
Between Groups
Within Groups
Total
(Combined)
df
1.0
F
.1
Sig.
.804
(Combined)
76.0
77.0
1.0
8.8
.004
(Combined)
76.0
77.0
1.0
.7
.399
(Combined)
76.0
77.0
1.0
.1
.732
76.0
77.0
4
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
From Tables 4 and 5 above, based on ANOVA test, it is found that male and female
members are not statistically different from each other in terms of average number of
weeks since registering with Drupal.org, total commits, and number of projects covered.
However, in terms of commits to Drupal core, female core developers on average
contribute more compared with male developers.
Tables 6 and 7 present descriptive statistics about core developers’ involvement in
module development, theme development, and educational activities. Module
development involvement is reflected on whether the member is involved in patch
contribution to existing modules, new module development, issue queue contribution,
project translation, project application review, participation of module test, and
development of installation profiles. Educational involvement is reflected by whether the
developer participates in forum discussions and Internet Relay Chat (IRC)
communications, the number of conference attended, and documentation contribution.
Theme development involvement is based on one question in the profile page.
Table 6: Module Development Involvement Comparison: Female vs. Male
Gender
Drupal
Association
Membership
Patches
Modules
Installation
Profiles
Issue
Queue
Translation
automated
test
Reviewed
project
applications
Female
5
6
6
1
7
1
5
1
Percentage
(out of 7)
71%
86%
86%
14%
100%
14%
71%
14%
Male
35
63
60
12
43
18
35
18
Percentage
(out of 71)
49%
89%
85%
17%
61%
25%
49%
25%
Table 7: Educational Activity and Theme Development Involvement
Educational Activity Involvement
Gender
forum
IRC
mentor new
contributors
Average Number of
Attended
Conferences until
2013 April
Female
2
5
2
6.7
Percentage
(out of 7)
28.6%
71.4%
28.6%
95.7%
Male
24
41
14
3.6
Percentage
(out of 71)
34%
58%
20%
5%
5
Average of
documentation
commits
368.6
Theme
Development
Involvement
2
28.6%
26.9
15
21%
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
In order to understand the levels of involvement for female and male core developers in
various community activities listed in Tables 6 and 7, overall module development
involvement score, educational involvement score, and the multi-role playing score are
calculated. Specifically, multi-role play is included since it has been found to be
positively associated with OSS success and innovativeness (Daniel et al. 2012). First, if
a developer is involved in one of those module development activities as presented in
Table 6, he/she will earn one point for module development involvement. The formula
used to calculate the overall individual module development involvement score is sum
of involvement in those 7 activities / 7*10. Second, the individual theme design
involvement score is derived by checking one question in the profile page. The formula
used is theme design involvement*10. Theme design involvement score will be 10 if the
core developer is indeed involved with theme development. Third, individual education
involvement score is calculated by checking whether the core developer participates in
forum discussions and Internet Relay Chat (IRC) communications, whether he/she
mentors new members, and the extent of conference participation (i.e., the number of
conference attended/the number of conferences available by the sampling date), and
documentation contribution (i.e., each individual’s commits/maximal number of commits
by a core developer). The formula used is sum of involvement of the 5 educational
activities/5 *10. The individual multi-role playing score is calculated by using the
formula: Module Development Involvement*Theme Development Involvement + Module
Development Involvement *Education involvement + Theme Development Involvement
*Education involvement.
Table 8 shows the average scores of educational, module development, and theme
development involvement and the average score of multi-role playing for male and
female core developers. Table 9 presents ANOVA test results on whether there are
statistically significant differences between female and male core developers in getting
involved in educational activities, module development, theme development activities,
and the multi-role playing. It is found that there are no differences between male and
female core developers in educational, module development, and overall multi-role
playing activity involvement.
Table 8: Multi-role Playing, Educational, and Module Development Involvement
Descriptive Statistics
Female
Male
Total
Multi-Role Play
60.26
Educational
Involvement
4.16
Module
Development
Involvement
5.51
Theme
Development
Involvement
2.86
N
7.00
7.00
7.00
7.00
Std. Deviation
93.73
3.06
1.92
4.88
Mean
37.96
2.81
5.01
2.11
N
71.00
71.00
71.00
71.00
Std. Deviation
56.14
2.11
2.36
4.11
Mean
39.97
2.90
5.05
2.18
N
78.00
79.00
78.00
78.00
Std. Deviation
59.93
2.23
2.32
4.16
Gender
Mean
6
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
Table 9: ANOVA Test: Multi-role Playing, Educational Involvement, Module
Development Involvement, and Theme Development: Male Vs. Female Core
Developers
Multi-RolePlay
* Gender
Educational
Involvement *
Gender
Module
Development
Involvement *
Gender
Theme
Development
Involvement *
Gender
Between Groups
(Combined)
df
1
Within Groups
76
Total
Between Groups
(Combined)
Within Groups
Total
Between Groups
(Combined)
77
2
76
78
1
Within Groups
Total
76
77
Between Groups
(Combined)
1
Within Groups
76
Total
77
F
.880
Sig.
.351
1.892
.158
.294
.589
.202
.654
4. Findings
Through profile data analysis, it is found that the majority of Drupal core developers are
coming from developed countries and especially from US. It is also found that female
core developers are not different from their male co-developers in terms of average
number of weeks since registering with Drupal.org, overall total commits, and the
number of projects covered. However, in terms of commits to the Drupal core, female
core developers, on average, indeed contribute more compared with male core
developers. Third, no statistically significant differences are identified between male and
female core developers in getting involved in module development, theme
development, and educational activities. Lastly, for multi-role playing, no significant
difference is found either.
5. Summary and Conclusions
In this paper, profile data of core developers of Drupal are collected from the Drupal
community site Drupal.org. Descriptive statistics are presented and ANOVA tests are
used to identify any differences between male and female core developers in terms of
their involvement in Drupal community. These tests demonstrate that while male core
developers are still the dominant force for Drupal core development, female developers
who do get involved in core development activities perform equally well. Findings in this
paper related to core developers in general and comparisons between male and female
core developers in particular lay a foundation for future study of success factors for
Drupal - the award winning content management system. This line of research will help
advance our knowledge about success factors for open source software in general in
an accumulative manner.
7
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
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Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
February 21, 2010
87
alpha5
drupal 7.0alpha4
drupal 7.0alpha3
drupal 7.0alpha2
drupal 7.0alpha1
Drupal 7.xdev
drupal 6.28
86
drupal 6.27
December 19, 2012
85
84
83
82
81
80
79
78
77
76
75
74
drupal 6.26
drupal 6.25
drupal 6.24
drupal 6.23
drupal 6.22
drupal 6.21
drupal 6.20
drupal 6.19
drupal 6.18
drupal 6.17
drupal 6.16
drupal 6.15
73
drupal 6.14
72
71
70
69
68
67
66
65
64
63
62
61
60
59
drupal 6.13
drupal 6.12
drupal 6.11
drupal 6.10
drupal 6.9
drupal 6.8
drupal 6.7
drupal 6.6
drupal 6.5
drupal 6.4
drupal 6.3
drupal 6.2
drupal 6.1
drupal 6.0
drupal 6.0rc4
drupal 6.0rc3
drupal 6.0rc2
drupal 6.0rc1
May 2, 2012
February 29, 2012
February 1, 2012
February 1, 2012
May 25, 2011
May 25, 2011
December 15, 2010
August 11, 2010
August 11, 2010
June 2, 2010
March 4, 2010
December 16, 2009
September 16,
2009
July 1, 2009
May 13, 2009
April 30, 2009
February 25, 2009
January 14, 2009
December 11, 2008
December 10, 2008
October 22, 2008
October 8, 2008
August 14, 2008
July 9, 2008
April 9, 2008
February 27, 2008
February 13, 2008
Appendix: Drupal Releases
92
Assigned
Version
Number
for
Graphing
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
Release
91
Initial Post Date
90
Drupal 8.xdev
drupal 7.22
drupal 7.21
drupal 7.20
drupal 7.19
drupal 7.18
drupal 7.17
drupal 7.16
drupal 7.15
drupal 7.14
drupal 7.13
drupal 7.12
drupal 7.11
drupal 7.10
drupal 7.9
drupal 7.8
drupal 7.7
drupal 7.6
drupal 7.5
drupal 7.4
drupal 7.3
drupal 7.2
drupal 7.1
drupal 7.0
drupal 7.0rc4
drupal 7.0rc3
drupal 7.0rc2
drupal 7.0rc1
drupal 7.0beta3
drupal 7.0beta2
drupal 7.0beta1
drupal 7.0alpha7
drupal 7.0alpha6
drupal 7.0-
September 9, 2009
89
April 3, 2013
March 7, 2013
February 20, 2013
January 16, 2013
December 19, 2012
November 7, 2012
October 17, 2012
August 1, 2012
May 2, 2012
May 2, 2012
February 1, 2012
February 1, 2012
December 5, 2011
October 26, 2011
August 31, 2011
July 28, 2011
July 27, 2011
July 27, 2011
June 30, 2011
June 30, 2011
May 25, 2011
May 25, 2011
January 5, 2011
88
December 30, 2010
December 23, 2010
December 11, 2010
December 1, 2010
November 14, 2010
October 23, 2010
58
October 7, 2010
57
September 16,
2010
56
July 9, 2010
55
May 23, 2010
9
April 26, 2010
March 21, 2010
January 15, 2010
July 2, 2008
January 16, 2013
February 8, 2008
January 30, 2008
January 10, 2008
December 20, 2007
Proceedings of 7th Global Business and Social Science Research Conference
13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9
49
48
47
drupal 6.0beta4
drupal 6.0beta3
drupal 6.0beta2
drupal 6.0beta1
Drupal 6.xdev
Drupal 5.23
Drupal 5.22
Drupal 5.21
46
Drupal 5.20
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
Drupal 5.19
Drupal 5.18
Drupal 5.17
Drupal 5.16
Drupal 5.15
Drupal 5.14
Drupal 5.13
Drupal 5.12
Drupal 5.11
Drupal 5.10
Drupal 5.9
Drupal 5.8
Drupal 5.7
Drupal 5.6
Drupal 5.5
Drupal 5.4
Drupal 5.3
Drupal 5.2
Drupal 5.1
Drupal 5.0
Drupal 5.0rc2
Drupal 5.0rc1
Drupal 5.0beta2
Drupal 5.xdev
Drupal 5.0beta1
Drupal
4.7.11
Drupal
4.7.10
Drupal 4.7.9
54
53
52
51
50
25
24
23
22
21
20
19
18
September 15,
2007
17
16
15
14
13
12
11
10
Drupal 4.7.8
Drupal 4.7.7
Drupal 4.7.6
Drupal 4.7.5
Drupal 4.7.4
Drupal 4.7.3
Drupal 4.7.2
Drupal 4.7.1
October 17, 2007
July 26, 2007
January 29, 2007
January 5, 2007
October 18, 2006
August 2, 2006
June 2, 2006
May 25, 2006
November 13, 2006
9
Drupal 4.7.0
May 1, 2006
August 11, 2010
March 4, 2010
December 16, 2009
September 16,
2009
July 1, 2009
May 13, 2009
April 30, 2009
February 25, 2009
January 14, 2009
December 11, 2008
December 10, 2008
October 22, 2008
October 8, 2008
August 14, 2008
July 23, 2008
July 9, 2008
January 29, 2008
January 10, 2008
December 6, 2007
December 5, 2007
October 17, 2007
July 26, 2007
January 30, 2007
January 15, 2007
8
December 5, 2007
November 21, 2007
October 17, 2007
7
6
5
4
3
2
1
January 10, 2007
December 15, 2006
November 28, 2006
November 11, 2006
October 31, 2006
January 10, 2008
December 6, 2007
December 5, 2007
10
Drupal
4.7.0-rc4
Drupal
4.7.0-rc3
Drupal
4.7.0-rc2
Drupal
4.7.0-rc1
Drupal
4.7.0-beta6
Drupal
4.7.0-beta5
Drupal
4.7.0-beta4
Drupal
4.7.0-beta3
April 28, 2006
April 15, 2006
April 7, 2006
March 31, 2006
March 14, 2006
March 2, 2006
January 26, 2006
January 9, 2006