* Tight integration with native Rust [functions](https://rhai.rs/book/rust/functions.html) and [types]([#custom-types-and-methods](https://rhai.rs/book/rust/custom.html)), including [getters/setters](https://rhai.rs/book/rust/getters-setters.html), [methods](https://rhai.rs/book/rust/custom.html) and [indexers](https://rhai.rs/book/rust/indexers.html).
* Freely pass Rust values into a script as [variables](https://rhai.rs/book/language/variables.html)/[constants](https://rhai.rs/book/language/constants.html) via an external [`Scope`](https://rhai.rs/book/rust/scope.html) - all clonable Rust types are supported; no need to implement any special trait. Or tap directly into the [variable resolution process](https://rhai.rs/book/engine/var.html).
* Built-in support for most common [data types](https://rhai.rs/book/language/values-and-types.html) including booleans, [integers](https://rhai.rs/book/language/numbers.html), [floating-point numbers](https://rhai.rs/book/language/numbers.html) (including [`Decimal`](https://crates.io/crates/rust_decimal)), [strings](https://rhai.rs/book/language/strings-chars.html), [Unicode characters](https://rhai.rs/book/language/strings-chars.html), [arrays](https://rhai.rs/book/language/arrays.html) and [object maps](https://rhai.rs/book/language/object-maps.html).
* Relatively little `unsafe` code (yes there are some for performance reasons), and `unsafe` code is only used for type casting, never to get around the borrow checker.
* Few dependencies - currently only [`smallvec`](https://crates.io/crates/smallvec), [`num-traits`](https://crates.io/crates/num-traits), [`ahash`](https://crates.io/crates/ahash) and [`smartstring`](https://crates.io/crates/smartstring).
* Scripts are [optimized](https://rhai.rs/book/engine/optimize.html) (useful for template-based machine-generated scripts).
* Easy custom API development via [plugins](https://rhai.rs/book/plugins/index.html) system powered by procedural macros.
* [Function overloading](https://rhai.rs/book/language/overload.html) and [operator overloading](https://rhai.rs/book/rust/operators.html).
* Dynamic dispatch via [function pointers](https://rhai.rs/book/language/fn-ptr.html) with additional support for [currying](https://rhai.rs/book/language/fn-curry.html).
* [Closures](https://rhai.rs/book/language/fn-closure.html) (anonymous functions) that can capture shared values.
* Some syntactic support for [object-oriented programming (OOP)](https://rhai.rs/book/language/oop.html).
* Organize code base with dynamically-loadable [modules](https://rhai.rs/book/language/modules.html), optionally [overriding the resolution process](https://rhai.rs/book/rust/modules/resolvers.html).
* Support for [minimal builds](https://rhai.rs/book/start/builds/minimal.html) by excluding unneeded language [features](https://rhai.rs/book/start/features.html).
* _Don't Panic_ guarantee - Any panic is a bug. Rhai subscribes to the motto that a library should never panic the host system, and is coded with this in mind.
* [Sand-boxed](https://rhai.rs/book/safety/sandbox.html) - the scripting engine, if declared immutable, cannot mutate the containing environment unless [explicitly permitted](https://rhai.rs/book/patterns/control.html).
* Rugged - protected against malicious attacks (such as [stack-overflow](https://rhai.rs/book/safety/max-call-stack.html), [over-sized data](https://rhai.rs/book/safety/max-string-size.html), and [runaway scripts](https://rhai.rs/book/safety/max-operations.html) etc.) that may come from untrusted third-party user-land scripts.
* Track script evaluation [progress](https://rhai.rs/book/safety/progress.html) and manually terminate a script run.
