Contributors Turnover

Master on Free Software

Contributors turnover

Dynamics of the libre software community

Israel Herraiz<[email protected]>

A Coruña, November 17th 2007

mailto:[email protected]


Summary

● How sensible is a project to the turnover of its main contributors?

● What would happen to Linux if Linus Torvalds is hit by a bus?

● What if the most important developers of Debian abandon the project and go for Ubuntu?


Main contributors

● 80% of the work is done by 20% of the people


Top contributors go away

● What would happen?● Are they “code gods”?


Methodology

● Divide the history in 10 intervals● Identify the top contributors in each

period● Track the history of those contributors in

all the history of the project


Methodology

● Results are given as plots and indexes


Generations index

Group 1 10 7 6 5 4Group 2 4 9 5 2 1Group 3 2 8 14 3 2Group 4 0 1 1 9 4Group 5 0 0 0 8 20

Period 1Period 2Period 3Period 4Period 5

● Absolute Matrix


Generations index


Kind of projects: code gods


Code gods. Heatmap of the matrix


Code gods. 3D Maps. Relative.


Code gods. 3D Map. Absolute


Kind of projects: generational relay


Generations. Heatmap


Generations. 3D Map. Relative


Generations. 3D Map. Absolute


Kind of projects: mixed behaviour


Mixed behaviour. Heatmap


Mixed behaviour. 3D Map. Relative


Mixed behaviour. 3D Map. Absolute


Summarising

● Three kind of projects:– Code gods

● Index ~ 100 %

– Generational relay● 0 % < Index < 100 %

– Mixed behaviour● Index ~ 0 %


Age vs. Index


Index distribution


Conclusions

● Detection of events in projects. Reverse engineering of the history of the project.

● Index gives us the kind of project● Most of the projects show a generational

relay● So most of the projects are not sensible to

contributor turnovers

Technology

Contributors Turnover