Jochen Liedtke

Who was Jochen Liedtke?

Jochen Liedtke was a German computer scientist, noted for his work on microkernels, especially the creation of the L4 microkernel family.

In the mid-1970s Liedtke studied for a diploma degree in mathematics at the University of Bielefeld. His thesis project was to build a compiler for the ELAN programming language, which had been launched for teaching programming in German schools; the compiler was written in Elan itself. After his graduation in 1977, he remained at Bielefeld and worked on an Elan environment for the Zilog Z80 microprocessor. This required a run-time environment, which he called Eumel. Eumel grew into a complete multi-tasking, multi-user operating system supporting orthogonal persistence, which started shipping in 1980 and was later ported to Zilog Z8000, Motorola 68000 and Intel 8086 processors. As these processors lacked memory protection, Eumel implemented a virtual machine which added the features missing from the hardware. More than 2000 Eumel systems shipped, mostly to schools but also to legal practices as a text-processing platform.