Guile is an implementation of the Scheme programming language and is the GNU project's official extension language.
Guile support in gdb follows the Python support in gdb reasonably closely, so concepts there should carry over. However, some things are done differently where it makes sense.
gdb requires Guile version 2.0 or greater. Older versions are not supported.
Guile scripts used by gdb should be installed in data-directory/guile, where data-directory is the data directory as determined at gdb startup (see Data Files). This directory, known as the guile directory, is automatically added to the Guile Search Path in order to allow the Guile interpreter to locate all scripts installed at this location.