OpenCerts

Ethereum Attestation Service (EAS) is an infrastructure public good for making attestations onchain or offchain about anything.

Unlock Protocol is a protocol that enables creators to monetize their content with a few lines of code in a fully decentralized way. It focuses on memberships and subscription NFTs with features like time constraints, pricing updates, and recurring payments. It is trusted by thousands of developers and community members for building next-generation membership products