Presentation on a preliminary empirical study we did on actual open source license proliferation.

1. License proliferation
An extremely naive quantitative analysis
based on FLOSSMOLE data
April 4th, 2013
Walter van Holst
w.van.holst@mitopics.nl
Independent IT consultancy through its combination of technical, business and legal expertise

2. Programme
 Background
 Methodology
 Initial results
 Conclusions/Q+A

3. License proliferation
 In 2009 Mitopics sponsored a Master’s thesis on
license proliferation
 Qualitative analysis
 Contradictory results
 Time for a quantitative follow-up
 Little data available in 2009

4. Freecode dataset
 Published since about 2005
 Jump in quality around 2009

5. License proliferation measurements
 What is license proliferation?
 The distribution of licenses across licenses?
 Or just a compatibility problem?
 And is one-way compatibility enough?

6. How do we value compatibility
 Extremely naively:
 Treat open source projects as nodes of a network
 Consider any combination as a desirable one
 Treat any combination as of equal value as
others
 Metcalfe’s law: n*(n-1)/2

7. Programme
 Background
 Methodology
 Initial results
 Conclusions/Q+A

8. Methodology
 FLOSSmole contains a wealth of data
 However…
 … quite a lot of pollution
 So far the Freecode (formerly Freshmeat) code
set is most useful, but only after 2009

9. 2009
GPL
72%
LGPL
8%
BSD
7%
GPL2
3%
GPL3
2%
MIT
2%
Artistic License
2%
APL2
1%
OSI Approved
1%
MPL
1% APL
1%
0% 0%

10. What are the network values
GPL 38171 728493535
LGPL 7242 26219661
BSD+MIT 3651 6663075
GPL2 32738 535871953
GPL3 32868 540136278
Artistic License 4915 12076155
APL2 4612 10632966
MPL 4878 11895003
APL 4252 9037626
Total potential 38674 747819801
Value loss 19326266

11. So…
 … license proliferation was not a massive
problem in 2009 despite the occurence of
several incompatible licenses

12. GPL
63%
LGPL
9%
BSD
8%
GPL3
5%
GPL2
5%
MIT
3%
Artistic License
2%
APL2
2% Other
1%
MPL
1%
APL
1% 0% 0%
2010
Total potential 534595951
Value loss 30771055

13. GPL
61%LGPL
9%
BSD
9%
GPLv3
6%
GPL2
5%
MIT
3%
APL2
2%
Artistic License
2%
Other
1%
MPL
1%
APL
1%
2011
Potential value 565908903
Value loss 56417822

14. GPL
59%
LGPL
9%
BSD
9%
GPLv3
7%
GPL2
5%
MIT
4%
APL2
2%
Artistic
License
2%
Other
1%
MPL
1%
APL
1%
2012
Potential value 599601135
Value loss 79779489

15. GPL
58%
LGPL
9%
BSD
9%
GPLv3
7%
GPL2
5%
MIT
4%
APL2
3%
Artistic
License
2%
Other
1%
MPL
1%
APL
1%
GPL2+
0%
2013
Potential value 621580911
Value loss 60372158

16. Programme
 Background
 Methodology
 Initial results
 Conclusions/Q+A

17. Some cautious conclusions
 Fragmentation was not a big problem to begin
with
 Grew with the rift within the GPL-communities
 May be subsiding again, thanks to adoption of
APL2 and GPL2+