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.

uPort is developing a self-sovereign identity platform for the Ethereum blockchain. It will consist of a wallet that will allow users to sign transactions and manage their keys and data more easily, as well as tools that will allow developers to issue credentials and request data from other DApps that use the paltform. uPort 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.