Meta-circular evaluation is discussed at length in 4.1: The Metacircular Evaluator, in SICP.
Meta-circular implementations are suited for extending the language they are written in. They are also useful for writing tools that are tightly integrated with the programming language, such as sophisticated debuggers. A language designed with a meta-circular implementation in mind is often more suited for building languages in general, even ones completely different from the host language.
Languages designed from the ground up with a meta-circular implementation:
Languages with third-party meta-circular implementations: