I wrote about all this recently on my blog: https://www.coactivate.org/projects/disintermedia/blog/2018/04/19/funding-the-web-commons-or-how-do-you-fund-crowdfunding/
GNU Taler is a great concept, and I hope they can find some banks who will work with them. Until that happens though, it's not an option.
Liberapay is a fork of Gratipay, which was sadly nobbled and destroyed by Safer Spaces Policing. My understanding is that Liberapay was set up as a replacement by some of the people involved in that Safer Spaces Policing, which makes me a little wary of it, but I'm still signed up there. OpenCollective is another similar system, run by some of the people behind Democracy Earth Foundation.
There is also Flattr 2.0, which requires a project to do very little to become eligible for payments (just sign up, enter your domain name, and put some code in the heads of your pages), but TBH I wouldn't expect a lot of revenue from it for a software project. Also Ko-Fi, which is emulating the failed Flattr 1.0 model, and requires a PayPal account.
