Funding for developer tools
3 open grants, hackathons, bounties and fellowships for developer tools, each checked against the organizer's official page.

Bounty
Rolling
Microsoft Open Source Bounty Program
Microsoft pays $750 to $15,000 USD for qualifying security vulnerabilities in open source projects such as Visual Studio Code, TypeScript, PowerShell 7 and the Azure SDKs. Submissions are accepted on a rolling basis.
AmountBounty awards from $750 to $15,000 USD
DeadlineRolling
ByMicrosoft Security Response Center

Bounty
Rolling
ProjectDiscovery OSS Bounty Program
ProjectDiscovery pays bounties for bug fixes, features, performance work and docs in its open source security tools. Each issue shows its reward. Open to anyone, no deadline.
AmountNot stated
DeadlineRolling
ByProjectDiscovery

Grant
Rolling
Tether Developer Grants Program
Tether pays developers roughly $1,500 to $4,000 per completed task on its open stack for local first AI and payments. Applications for active grants are open with no deadline.
AmountRoughly $1,500 to $4,000 per completed task
DeadlineRolling
ByTether