The Service Manager is a library for opaquely managing service process launch, sandboxing, and lifetime; and for brokering Mojo interface connections among services.
The Service Manager must be configured with a static set of declarative service definitions. The embedder API provides a means of embedding core Service Manager functionality into a standalone executable, delegating configuration and assorted implementation details to the embedder.
As one example, the Content layer of Chromium embeds the Service Manager via this API, and there it's used [WIP] to drive all process management and IPC setup across the system.
This API is a work in progress, and more details will be documented here as the API is stabilized.