Some projects have adopted donation systems with different grades of success. However this really requires having a combination of factors to work out, such as

Some projects have adopted donation systems with different grades of success. However this really requires having a combination of factors to work out, such as people actually needing the product, developers not being toxic in communication, the project and developers actually being around for some time to gather a dedicated following. Examples: http://www.ardour.org/ http://www.ardour.org/ https://godotengine.org/ https://godotengine.org/ https://rpcs3.net/ https://rpcs3.net/