🚀 go-pugleaf

I'm new to Mac (as a programmer); I am pretty familiar with Windows,
and I came from a Lisp background. The Windows and Mac are not
dissimilar, but I can't seem to find the analog to Windows dynamic
link libraries (DLLs).  DLLs are a nice way to share code among
Windows modules (both applications and other DLLs); in fact, Windows
itself appears as of DLLs.

The distinguishing features of DLLs are:

* Ability to link to export procedures by name.  Windows supplies a
primitive called GetProcAddress for this purpose. Sometimes, the act
of doing this is called ``dynamic dynamic linking.''

* Ability to use procedures from compiled code, assumed you had the
right headers, and the linker knew that those external procedures came
from a dynamic link library.

* Ability to use other DLL functions. In other words, a DLL can use
all the system services, within the bounds of their limitations.

Is there any single facility that would do the same on the Mac ? I was
thinking of two possiblities:

* Drivers. For example, ATM is a driver, and offers ATM-specific
services to programs that know about its existence.

* Code resources in shared file.

So, what DO people do about shared libraries on the Mac ?