All people who contribute to Duplicati are volunteers. We do not get paid, but use our spare time and private resources to keep everything running. Donations help us take out larger chunks of time to work on Duplicati, pay for hosting and service fees, and generally show us your appreciation for our work on Duplicati.
OpenCollective
If you are a company and want to support the project, we recommend to donate through Duplicati OpenCollective. OpenCollective is a registered company that issues receipts for donations. That way your donation can be officially booked as an expense in your company.
Furthermore, OpenCollective shows how the donated money is spent by the project members. Note that OpenCollective charges a percentage of the donated amount for their handling services.
PayPal
We also accept Donations through the Duplicati PayPal donation page. PayPal donations have so far been used for paying various hosting expenses.
Crypto currencies
We also accept donations in various crypto currencies. Feel free to use the one that you like best. Also, feel free to ask for your favourite currency to be supported.
Please double check the recipient address, and the token type, before sending any tokens. Crypto currencies are irreversible, so your tokens will be lost if you send it to a wrong address or wrong chain.
We arbitrarily decided to accept the following crypto currencies, and suggest using Shapeshift.io if you want to donate with another currency.
Donate with Bitcoin

Donate with Ethereum

Donate with Bitcoin Cash

Donate with Sia

Donate with Storj

Donate with Litecoin

Donate with Feathercoin

Donate with Neo

BountySource
If you want to back a specific feature, first make sure that it is registered as an issue on Github, then pledge money for the issue on Bounty Source. The person who submits the code that closes an issue can claim the money. The person claiming the bounty does not have to be a Duplicati team member. Backing an issue directly is an incentive for people to contribute to Duplicati, for the benefit of everyone.