Open source in academia would not be possible without extensive funding support. This support breaks down in two main ways: governmental bodies and private philanthropy. There are exceptions.
Each country tends to have their own particular funding landscape.
This list is incomplete. Please add to it!
New Zealand has a complicated funding relationship. Previously, the sciences were all held under the same department, the Department of Scientific and Industrial Research. This was split in 1992 into separate Crown Research Institutes (CRIs).
A full list is here.
The following funding opportunities have been taken from the open-funding GitHub repository and are subset of funding specifically relevant to academia. Sorted alphabetically.