Throughout this time the promise of a "true" microkernel was not yet being delivered. These early Mach versions included the majority of 4.3BSD in the kernel, a system known as POE Server, resulting in a kernel that was actually larger than the UNIX it was based on. The idea, however, was to move the UNIX layer out of the kernel into user-space, where it could be more easily worked on and even replaced outright. Unfortunately performance proved to be a major problem, and a number of architectural changes were made in order to solve this problem. Unwieldy UNIX licensing issues were also plaguing researchers, so this early effort to provide a non-licensed UNIX-like system environment continued to find use, well into the further development of Mach.