Gosu (programming language)

Gosu
Designed byScott McKinney
DeveloperGuidewire Software, open source contributors
First appearedNovember 11, 2010 (2010-11-11)
Stable release
1.18.7  / 4 December 2025 (4 December 2025)
Typing disciplinestatic
PlatformExecute on Java virtual machine, statically and dynamically compiles to bytecode
OSany supporting JVM
LicenseApache 2.0
Filename extensions.gs, .gsp, .gst, .gsx
Websitegosu-lang.github.io
Influenced by
Java, C#
Influenced
Kotlin

Gosu formerly GScript, is a statically typed general-purpose programming language that runs on the Java virtual machine. Its influences include Java, C#, and ECMAScript. Development of Gosu began in 2002 internally for Guidewire Software, and the language saw its first community release in 2010 under the Apache License 2.0.

Gosu can serve as a scripting language, having free-form Program types (.gsp files) for scripting and statically verified Template files (.gst files). Gosu can optionally execute these and all other types directly from source code with no precompiling, which also distinguishes it from other static languages.