Donation and enterprise level support is what comes to my mind. Also depending upon what you are developing, running a training program could bring in some extra cash.
When you reach certain level on development, funds might also come in from bigger industry. But its tough to get funds upfront no matter what the source is.
May be you can look into what light table did - https://www.kickstarter.com/projects/ibdknox/light-table
kluck|10 years ago
Commercial support and training: yes, but for that the software has to exist. A good idea for later on though.
ssapkota|10 years ago