Liberapay is a French crowdfunding membership platform which is popular among free software projects. It is ran by a french non-profit organization founded in 2015. It does not support one-time donations, only recurring donations
Liberapay uses it's own crowdfunded platform to fund itself. It has zero fees apart from the required payment processor fees it has to pay which makes it overall cheaper than alternatives like Patreon and SubscribeStar.
Liberapay supports 33 different currencies including the EURO and USD.
Liberapay lets you "connect" accounts on a number of well-known platforms including Microsoft GitHub, Twitter, Mastodon, YouTube, GitLab, Facebook, Twitch, Bitbucket and Pleroma. It is also possible to add website domains.
The developers of Mastodon are using Liberapay as a crowdfunding platform themselves. Other free software projects like the game Battle for Wesnorth and the Matrix messaging system are also using Liberapay to secure backing.