These are Dylan bindings for the gobject-introspection library (reference documentation).
To build them, you will need to build and install the gobject-introspection library first. On Ubuntu, this can be done by installing the libgirepository1.0-dev package.
You will also need OpenDylan 2012.1 or later.
This project also contains gir-generate-c-ffi which takes the
gobject-introspection metadata and generates the appropriate C-FFI
bindings for consumption by the Open Dylan compiler.
GIR metadata comes in 2 forms, XML files ending in .gir and binary
files compiled from the XML ending in .typelib. After installing
the gobject-introspection library, you may need to install additional
packages to have the compiled type libraries available. Compiled type
libraries are typically found in /usr/lib/girepository-1.0/ or
/usr/local/lib/girepository-1.0/. GIR files, which we do not
use, are found in /usr/share/gir-1.0/ or /usr/local/share/gir-1.0/.
On Ubuntu, the packages for installing this metadata typically begin
with the prefix gir1.2-.