OS X
Some loadable kernel modules in OS X can be loaded automatically. Loadable kernel modules can also be loaded by the kextload command. They can be listed by the kextstat command. Loadable kernel modules are located in application bundles with the extension .kext. Modules supplied with the operating system are stored in the /System/Library/Extensions directory; modules supplied by third parties are in various other directories.
Read more about this topic: Loadable Kernel Module