Web3 Foundation Grants
Web3 Foundation offers grants for open source software development and research around Substrate, Polkadot, Kusama and ink!. Applications and deliveries are tracked transparently on GitHub. Information regarding requirements, the application process, deliveries, etc. can be found in the Grants Program README. For guidance, there is also a list of previously accepted applications and a list of frequently asked questions.
Alternative Funding Sources
Check the alternative funding sources section on the Web3 Foundation grants repo for comprehensive information.
The Polkadot Treasury is a pot of on-chain funds collected through transaction fees, slashing, staking inefficiencies, etc. The funds held in the treasury can be spent on spending proposals. Both Polkadot and Kusama offer everyone the opportunity to apply for funding via the treasury. See:
Due to high demand and spamming issues, the Kusama faucet is no longer in operation. The Web3 Foundation has considered new ways to distribute KSM for people who need KSM to build.
Other Grant Programs
Below is a list of other grant programs in the Polkadot/Substrate ecosystem.