Some projects are pet projects. What people do when they want to polish their skills. Other people do it as a day job. Other people do it in combination with a

Some projects are pet projects. What people do when they want to polish their skills. Other people do it as a day job. Other people do it in combination with a paper... Then, companies might open source software if that software doesn't represent a competitive advantage. Other do it to improve their chances to be hired (github as resume)....