# Fast, portable, non-Turing complete expression evaluation
Common Expression Language (CEL) is a non-Turing complete language designed for simplicity, speed, safety, and portability. CEL is designed to be evaluated without a sandbox, making it ideal for use within latency critical applications.
## Features
- Familiar C-like syntax common to C++, Go, Java, and TypeScript.
- Gradual typing with first-class support for Protobuf and JSON types.
- High performance evaluators in C++ and Go with a rich set of standard operators.
## How Google uses Common Expression Language
Google uses CEL as the expression component of IAM and Firebase security policies, as well as within Istio Mixer configs.
