Slides for http://flux.cs.queensu.ca/oss4mde/files/2015/06/OSS4MDE15_paper_2.pdf (OSS4MDE'15)

1. 1
Assessing the Use of Eclipse MDE Technologies
in Open-Source Software Projects
D. Kolovos1, N. Matragkas2, I. Korkontzelos3,
S. Ananiadou3, and R. Paige1
1University of York, 2University of Hull
3University of Manchester

2. 2

3. 3Questions
• Which of these technologies demonstrate
significant adoption in open-source
projects?
• Is the activity related to these
technologies increasing or decreasing
over time?
• What is the size of the community of
GitHub developers who are familiar with
these technologies?

4. 4Methodology
• Identify concrete technologies of interest
• Compose GitHub queries based on file
extensions and keywords
• Filter out irrelevant results
– e.g file extension clashes
• Retrieve all commits involving files of
interest
• Unify data and analyse

5. 5Technologies
also requires a search term (that must appear in the content of the retrieved
files) to also be included in the query. After manual experimentation we iden-
tified the extensions and search terms in Table 1, which provided the largest
number of relevant results for each technology. We also manually sampled the
returned results to ensure that no irrelevant files were returned. This was the
Table 1: File extensions and search terms per technology
Techn. Ext. Search Term Techn. Ext. Search Term
ATL atl rule QVTo qvto transformation
Emfatic emf class Acceleo mtl template
EGL* egl var IncQuery eiq pattern
Eugenia* ecore ”gmf.diagram” GMF gmfgraph figure
EOL* eol var Xtext xtext grammar
ETL* etl transform Ecore ecore EClass
EVL* evl context OCL ocl context
Sirius odesign node Henshin henshin rule
MOFScript m2t texttransformation Kermeta kmt class
Xcore xcore class JET javajet jet
EMFText cs syntaxdef Xpand xpt for
case for all technologies except EGL and Acceleo. Files with a .egl extension
that contain the search term var can be either Epsilon Generation Language

6. 61000 Results/Query L
• GitHub returns the number of files that
meet the query's conditions
– … but only details about 1,000 of them
• Repository
• Path in the repository
• Snippet
• In the first round we collected all
repositories we could and we queried
them again

7. 7Search Results
them to be retrieved). To retrieve details for additional files of interest, we col-
lected all repositories returned by a first round of queries, and we queried these
repositories again for all file extensions of interest. The number of search results
and the number of actual files that we managed to retrieve the details of are
displayed in Table 2. This endeavour revealed that GitHub’s search interface
Table 2: Number of search results and retrieved files per technology
Technology Search
Results
Retrieved
Files
Technology Search
Results
Retrieved
Files
Ecore 15038 9629 QVTo 1247 1396
Xpand 7005 4974 GMF 1138 1100
Acceleo 6091 3158 Emfatic 525 510
JET 5323 3682 Sirius 428 503
OCL 3131 2418 EMFText 375 365
Xtext 2272 1605 Kermeta 339 343
ATL 1404 1481 Xcore 305 313
Epsilon 1352 1765 IncQuery 187 192
Henshin 1281 1142 MOFScript 34 34
is not particularly reliable. For example, after the dataset expansion phase we
have collected details for 1481 ATL files, 77 more than the number returned
by GitHub’s search interface in our first search (1404)). Similar discrepancies

8. 8Commit Collection
• Collected all commits for all files of
interest
– Commit time
– Developer and committer ids/email
addresses
• Grouped them by developer
– Used the committers' email addresses as IDs

9. 9Unification
403 commits. We have made the model and its metamodel availab
ithub. com/ kolovos/ datasets/ tree/ master/ github-mde so that the results p
ext section can be independently reproduced and verified.
Fig. 1: The Unification Metamodel
Metamodel and data available under http://github.com/kolovos/datasets/tree/master/github-mde

10. 10E
core
(15038)
X
p
an
d
(7005)
A
cceleo
(6091)
JE
T
(5323)
O
C
L
(3131)
X
tex
t
(2272)
E
p
silon
(1765)
A
T
L
(1481)
Q
V
T
o
(1396)
H
en
sh
in
(1281)
G
M
F
(1138)
E
m
fatic
(525)
S
iriu
s
(503)
E
M
F
T
ex
t
(375)
K
erm
eta
(343)
X
core
(313)
In
cQ
u
ery
(192)
M
O
F
S
crip
t
(34)
0
5,000
10,000
15,000
NumberofFilesonGitHub
5
1,0
1,5
EstimatednumberofGitHubRepositories

11. 11E
core
(1342)
X
tex
t
(660)
X
p
an
d
(231)
G
M
F
(228)
A
cceleo
(216)
JE
T
(164)
A
T
L
(151)
E
p
silon
(147)
E
m
fatic
(104)
X
core
(102)
Q
V
T
o
(76)
S
iriu
s
(75)
E
M
F
T
ex
t
(58)
In
cQ
u
ery
(45)
O
C
L
(42)
K
erm
eta
(19)
H
en
sh
in
(13)
M
O
F
S
crip
t
(7)
0
500
1,000
1,500
EstimatednumberofGitHubRepositories

12. 12E
core
(1481)
X
tex
t
(646)
X
p
an
d
(308)
G
M
F
(285)
A
cceleo
(222)
JE
T
(205)
A
T
L
(173)
E
p
silon
(158)
E
m
fatic
(115)
Q
V
T
o
(104)
S
iriu
s
(90)
X
core
(77)
O
C
L
(59)
E
M
F
T
ex
t
(52)
In
cQ
u
ery
(38)
H
en
sh
in
(24)
K
erm
eta
(21)
M
O
F
S
crip
t
(9)
0
500
1,000
1,500
EstimatednumberofDevelopers
5,0
10,0
15,0
20,0
25,0
CommitsperYear

13. 132003
(3)
2004
(208)
2005
(480)
2006
(539)
2007
(1700)
2008
(1180)
2009
(2602)
2010
(4402)
2011
(7654)
2012
(10511)
2013
(14560)
2014
(23979)
0
5,000
10,000
15,000
20,000
25,000
CommitsperYear

14. 142003
(1)2004
(4)
2005
(47)
2006
(54)
2007
(372)
2008
(315)
2009
(1014)
2010
(1262)
2011
(3418)
2012
(5144)
2013
(5933)
2014
(13208)
0
5,000
10,000
Lastupdatedfilesperyear
EstimatednumberofActiveGitHubRepositories

15. 15E
core
(715)
X
tex
t
(325)
E
p
silon
(104)
G
M
F
(103)
A
cceleo
(95)
A
T
L
(83)
X
p
an
d
(73)
E
m
fatic
(62)
S
iriu
s
(60)
JE
T
(57)
X
core
(51)
Q
V
T
o
(45)
In
cQ
u
ery
(28)
O
C
L
(26)
E
M
F
T
ex
t
(15)
H
en
sh
in
(11)
M
O
F
S
crip
t
(6)
K
erm
eta
(5)
0
200
400
600
EstimatednumberofActiveGitHubRepositories

16. TABLE III
% OF SHARED REPOSITORIES FOR EACH PAIR OF TECHNOLOGIES
ATL
Emfatic
Sirius
MOFScript
Xcore
EMFText
QVTo
Acceleo
IncQuery
GMF
Xtext
Ecore
OCL
Henshin
Kermeta
JET
Xpand
Epsilon
ATL n/a 11 0 1 0 5 4 9 0 11 20 83 3 1 0 3 7 16
Emfatic 16 n/a 0 1 0 4 6 7 0 34 9 85 1 0 0 1 10 58
Sirius 0 1 n/a 0 1 0 1 25 2 1 30 80 1 1 1 4 4 5
MOFScript 42 28 0 n/a 0 0 14 0 0 14 0 85 0 0 0 0 14 0
Xcore 0 0 0 0 n/a 0 0 1 1 1 42 36 1 0 0 4 5 3
EMFText 15 8 0 0 0 n/a 1 8 0 10 5 87 3 0 1 5 5 10
QVTo 9 9 1 1 0 1 n/a 23 0 34 22 85 2 1 0 11 26 13
Acceleo 6 3 8 0 0 2 8 n/a 0 11 14 53 3 0 0 2 5 7
IncQuery 2 2 4 0 4 0 0 2 n/a 4 17 73 2 2 0 0 6 4
GMF 7 15 0 0 0 2 11 10 0 n/a 14 89 1 2 0 10 18 21
Xtext 4 1 3 0 6 0 2 4 1 5 n/a 68 1 0 0 1 17 3
Ecore 9 6 4 0 2 3 4 8 2 15 33 n/a 2 0 1 5 11 9
OCL 14 4 2 0 4 4 4 16 2 9 23 80 n/a 0 7 9 0 2
Henshin 15 0 7 0 0 0 7 15 7 38 15 92 0 n/a 0 0 38 15
Kermeta 5 0 5 0 0 5 0 5 0 0 21 73 15 0 n/a 0 5 0
JET 3 1 1 0 3 1 5 3 0 15 4 48 2 0 0 n/a 6 4
Xpand 4 4 1 0 2 1 8 4 1 18 51 65 0 2 0 4 n/a 6
Epsilon 17 41 2 0 2 4 6 11 1 32 17 87 0 1 0 5 10 n/a

17. 17Observations (1/2)
• A healthy number of GitHub repositories
(1,928)
• A substantial community of 2,195
developers
• Increasing number of commits on files
related to these technologies over the last
decade

18. 18Observations (2/2)
• Model-to-text transformation languages
(XPand, Acceleo and JET) appear to be more
widely used than model-to-model
transformation languages (ATL, QVTo,
Henshin)
• Technologies led by industry (Ecore, Xtext,
Xpand, GMF, Acceleo and JET) are more
widely used than those developed in
academia (Epsilon, ATL, Kermeta, Henshin).