Lettuceshare is released under a free software license called the AGPL. This means you can download it and run it yourself, if you're comfortable running a web server.
The term free software refers to free as in freedom: you are free to download and use the software subject to the terms of the license it is released under. In the case of Lettuceshare this basically means you must also share your modifications publicly. Free does not refer to the time of the developers :-) The software is developed as resources will allow, which includes current Lettuceshare users requesting and offering to pay for new features. If you're interested in helping in this way, please get in touch to discuss consulting rates.
You can also become a supporter of software development on Lettuceshare!
This is available as a yearly subscription for existing groups, which is paid at $50 per month along with hosting fees. As a subscriber, your group will be listed on the supporters page, and you will be able to contribute to the planning around development work for Lettuceshare for the year.