I get that majority of small open source projects are led by volunteers who consider it a hobby.<p>At the same time, some big projects can earn money by offering enterprise support [1], selling courses/certification [2] or by charging for repository packages. [3]<p>However, how do medium-sized players like Wireshark, GIMP or LibreOffice survive? I'm not sure that donations make a huge difference and it doesn't seem they have some support plans.<p>[1] Ubuntu: https://ubuntu.com/support<p>[2] RedHat: https://www.redhat.com/en/services/training-and-certification<p>[3] Conda package manager is free of charge but for using the Anaconda repository, enterprise users have to subscribe to a paid edition: https://www.anaconda.com/blog/anaconda-commercial-edition-faq
LibreOffice has sponsorship from companies that sell support etc around it and employ devs. Wireshark is afaik sponsored by companies too, both users and companies that sell trainings.