Microkernels were first developed in the 1980s to allow services to be more easily worked on, and separate them from the kernel code. Essentially, a microkernel is the minimal amount of software used for implementing an operating system. They consist of less than 10,000 lines of code and include IPC (interprocess communication), low-level address space management, and thread management.
Kernel, Operating System terms
Typical operating systems remove device drivers and file systems from the microkernel, running them in the user space instead.
