Gravity is a powerful, dynamically typed, lightweight, embeddable programming language written in C without any external dependencies (except for stdlib). It is a class-based concurrent scripting language with modern Swift -like syntax. Gravity supports procedural programming, object-oriented programming, functional programming, and data-driven programming. Thanks to special built-in methods, it can also be used as a prototype-based programming language. Gravity has been developed from scratch for the Creo project in order to offer an easy way to write portable code for the iOS and Android platforms. It is written in portable C code that can be compiled on any platform using a C99 compiler. The VM code is about 4K lines long, the multipass compiler code is about 7K lines and the shared code is about 3K lines long. The compiler and virtual machine combined add less than 200KB to the executable on a 64-bit system. What Gravity code looks like class Vector { // instance variables var x = 0 ; var y = 0 ; var z = 0 ; // constructor func init ( a = 0 , b = 0 , c = 0 ) { x = a; y = b; z = c; } // instance method (built-in operator overriding) func + ( v ) { if ( v is Int ) return Vector ( x + v , y + v , z + v ) ; else if ( v is Vector ) return Vector ( x + v . x , y + v . y , z + v . z ) ; return null; } // instance method (built-in String conversion overriding) func String ( ) { // string interpolation support return " [ \( x ) , \( y ) , \( z ) ] " ; } } func main ( ) { // initialize a new vector object var v1 = Vector ( 1 , 2 , 3 ) ; // initialize a new vector object var v2 = Vector ( 4 , 5 , 6 ) ; // call + function in the vector object var v3 = v1 + v2; // returns string "[1,2,3] + [4,5,6] = [5,7,9]" return " \( v1 ) + \( v2 ) = \( v3 ) " ; } Features multipass compiler dynamic typing classes and inheritance higher-order functions and classes lexical scoping coroutines (via fibers) nested classes closures garbage collection operator overriding powerful embedding API built-in unit tests built-in JSON serializer/deserializer optional semicolons Special thanks Gravity was supported by a couple of open-source projects. The inspiration for closures comes from the elegant Lua programming language; specifically from the document Closures in Lua . For fibers, upvalues handling and some parts of the garbage collector, my gratitude goes to Bob Nystrom and his excellent Wren programming language. A very special thanks should also go to my friend Andrea Donetti who helped me debugging and testing various aspects of the language. Documentation The Getting Started page is a guide for downloading and compiling the language. There is also a more extensive language documentation . Official wiki is used to collect related projects and tools. Where Gravity is used Gravity is the core language built into Creo ( https://creolabs.com ) Gravity is the scripting language for the Untold game engine ( https://youtu.be/OGrWq8jpK14?t=58 ) Community Seems like a good idea to make a group chat for people to discuss Gravity. Contributing Contributions to Gravity are welcomed and encouraged! More information is available in the official CONTRIBUTING file. Open an issue : if you need help if you find a bug if you have a feature request to ask a general question Submit a pull request : if you want to contribute License Gravity is available under the permissive MIT license.