All three of the major BSD derivatives have the ability to put parts of themselves in modules. They are all monolithic kernels, as is Linux. Monolithic, in ker

All three of the major BSD derivatives have the ability to put parts of themselves in modules. They are all monolithic kernels, as is Linux. Monolithic, in kernel speak, does not refer to having everything compiled in; it is more concerned about what is in kernel space (can do anything it wants with the hardware) and what is in user space (what is restricted at the hardware level to playing in its own memory). Monolithic kernels have pretty much everything in memory, and microkernels have pretty much everything in moderately-privileged userspace processes that talk to each other via message passing.