Guile

If you're looking to create flexible and customizable applications, you may want to consider using Guile. This library is specifically designed to make it easier for programmers to develop plug-ins or modules that users can use to customize their experience.

One of the key benefits of using extension languages like Guile is that it allows users to add features to a program without having to rewrite it entirely. This saves time and effort, and also allows different developers to work together to create new extensions.

Some well-known examples of successful applications that use extension languages include GNU Emacs and The GIMP. Guile itself is an interpreter for the Scheme programming language that can be easily incorporated into any program. This means that users have full access to the interpreter and can customize it to meet their specific needs.

Using Guile makes it much easier for users to customize your application without needing to understand its underlying structure. Instead, they can just learn how to use Guile and the access you've provided, and then start trading and sharing new features with other users. With Guile, you don't need to coordinate with your users or other developers to create new features - it all happens seamlessly in the background.