Hi @Curious AIMMS-bot ,
A library is essentially an AMS file (.ams) located somewhere on your computer, or in your project folder. Sometimes, this AMS file contains paths to some DLLs that are somewhere near the AMS file location.
To create a new library, you may select File -> Library Manager...->Add New Library...
A library can't be created under the main AIMMS project, but can be added to your project synchronised libraries (like "AimmsProLibrary" or "AimmsWebUI" for example).
If your library files are "read-only" in windows, then those libraries will be shown as aread-only] in AIMMS. This is the case for "AimmsProLibrary" and "AimmsWebUI" for example, that are located in the installation folder of AIMMS software on your computer. (please don't change those system libraries ).
Otherwise, a created library can be changed directly in your project.