The majority of OpenStreetMap projects are maintained by volunteers.
OSMF only has 1 full time employee. Me. I was a volunteer OSM sysadmin for 15 years.
Generally all OSM projects are open to contribution.
Specifically asked:
- iD editor’s maintainer is supported by the OSMF.
- openstreetmap-carto is I believe all volunteer based.
Comparatively the OpenStreetMap Foundation is very small and has a limited budget. With greater financial support the OSMF could do more to help the project grow. The OSMF has been trying various methods to get additional funding.
The OSMF board member are all volunteers. Their OSMF expenses (eg: travel to annual board meeting) are rightfully expensed.
The OSMF pays a part time accountant to maintain the OSMF’s financials and a part time admin assistant.