Https://bounties.network/ might be an option, you can also post non-coding related work on gitcoin. Source: about 2 years ago

Grab yer’ horse and saddle up. Bounties is another way to earn free cryptocurrency by completing certain tasks, hence the name. Started as a way to spread awareness (see a pattern here?), doing these objectives and tasks will reward you with a certain amount of a cryptocurrency depending on where the bounty is listed. Two great sites for bounties are https://bounty0x.io/ and https://bounties.network/. Source: about 3 years ago

I'm thinking of using some bug bounty type of services to speed up bugfixes and adding new features, anyone has experience with it? I mean services like https://www.bountysource.com/ , https://gitpay.me/ or https://issuehunt.io/. Source: almost 3 years ago

I don't think we have a good model for monetary rewards for maintenance. If Haskell.org was providing support contracts covering a wide range of libraries, I would guess a lot of companies would use the option. However, signing a support contract with a maintainer of every dependency I have is infeasible. Things like Gitpay (bounties for PRs) have been tried time and again, and they never take off. Source: about 3 years ago

Donate to the project, start a company employing devs, buy support from Canonical or RedHat or SuSE, pay for issues to be fixed through GitPay or BountySource. Source: about 3 years ago