You can support calcurse development in many different ways. If you know how to code, one of the best ways to contribute is to submit patches fixing bugs, adding features or improving overall code quality. We are also extremely grateful for donations. These donations are used to cover recurring costs, such as for our servers, and help us continue developing calcurse as open source software.
Note that due to repeated abuse of our donations form for fraudulent card testing, we no longer offer the option to donate less than 15€ (or $15). If you want to make a smaller donation, feel free to contact us using the email address from the previous paragraph.