Guile is described as 'The GNU Ubiquitous Intelligent Language for Extensions, the official extension language for the GNU operating system. It's an implementation of the Scheme programming language, supporting the Revised5 and most of the Revised6 language reports, as well as many SRFIs' and is a programming language in the development category. There are more than 25 alternatives to Guile for a variety of platforms, including Linux, Mac, Windows, BSD and Web-based apps. The best Guile alternative is Python, which is both free and Open Source. Other great apps like Guile are JavaScript, Lua, C# and Go (Programming Language).