Metadium is developing a blockchain protocol for Self-Sovereign Identity. Their goal is to allow users to own all aspects of their identity. Metadium's network is powered by the Ethereum-based META token.

3Box is developing an identity management platform for Ethereum-based DApps. Users will be able to create a profile that will allow them to sign in to DApps with one click. 3Box is a ConsenSys portfolio company.

The Sovrin Foundation is a non-profit organization dedicated to establishing the Sovrin network. Their goal is to create a purpose-built blockchahin, with a native token, that will facilitate creating and maintaining self-sovereign identities. The Sovrin token will provide incentives to value exchange that preserves privacy. It could also enable a global marketplace for digital credentials and personal data.
This is an important project that has lofty goals, but has the potential to revolutionize several major industries.