Pros and Cons of Microkernels: Thorvalds vs. Tanenbaum

In the second round of this famous debate Tanenbaum could have an edge over Thorvalds: Linus had won the orginal debate using the performance argument against microkernals. In the meantime systems have become faster and the problem foucs is much more on reliability and security than in previous years.

Looking at the basic security principles of isolation and POLA, the microkernel approach seems to be superior to a large monolithic kernel with ample ambient authority ready to be abused by drivers etc.

According to Tanenbaum microkernels - or what he calls multi-server operating systems - do not suffer from complicated distributed system algorithms because they use a global time (one system), operate in isolation and have benign failure properties.