Gosu (programming language)

Gosu is a statically-typed programming language that runs on the Java Virtual Machine released under the Apache 2. This general-purpose programming language is used in several open-source software projects including SparkGS and Ragnar DB among several others, and is widely used in the insurance industry via Guidewire Software's commercial products. The language borrows from several existing languages including Java, C#, and ECMAScript. A notable and unique feature is its Open Type System, which allows the language to be easily extended to provide compile-time checking and IDE awareness of information that is typically checked only at runtime in most other languages. Also of note is the language's ability to serve as both a full-featured general purpose language and as a concise scripting language. For instance, Gosu has free-form Program types (.gsp files) for scripting as well as statically verified Template files (.gst files). Gosu can optionally execute these and all other types directly from source without precompilation, which also distinguishes it from other static languages.

Gosu began in 2002 as a scripting language called GScript at Guidewire Software. It was used to configure business logic in Guidewire's applications and was more of a simple rule definition language. In its original incarnation it followed ECMAScript guidelines. Guidewire enhanced the scripting language over the next 8 years, and released Gosu 0.7 beta to the community in November 2010. The 0.8 beta was released in December 2010, and 0.8.6 beta was released in mid-2011 with additional typeloaders, making Gosu capable of loading XML schema definition files and XML documents as native Gosu types. The latest version is 1.10, released in January 2016, along with a new IntelliJ IDEA editor plugin.