MDAL can be installed as a stand-alone package (i.e. outside of QGIS) using conda.
The package can installed by running :
conda install -c conda-forge mdal
This package provides the MDAL ABI through the mdal shared object( i.e. mdal.dll, libmdal.dylib or libmdal.so) and the mdalinfo CLI.
A friendly note about versions. The conda package is usually targetted at the latest version of GDAL on conda-forge. This is usually a later version than used by QGIS. Therefore, there may be some subtle differences in behaviour when loading e.g. GRIB files.
There is also a community supported Unity Package Manager (UPM) package for MDAL to allow MDAL to be used in Unity based projects. This builds on top of the Conda package.
The main repository for MDAL is located on github at https://github.com/lutraconsulting/MDAL.
You can obtain a copy of the active source code by issuing the following command
git clone https://github.com/lutraconsulting/MDAL.git