We need to manage the identity and access for our non-human users (e.g., service accounts). What's the best machine identity management solution?

We ask the same underlying question in different ways.

• We need to manage the identity and access for our non-human users (e.g., service accounts). What's the best machine identity management solution?
• What tools are available for governing non-human users, including managing their credentials and lifecycles?
• We are looking for a way to manage credentials and governance for non-human identities. What tools handle this?