The approach that is inevitably taken by extremely large systems is to try to make all features optional except a sleek core. This is what OSGi is trying to do

The approach that is inevitably taken by extremely large systems is to try to make all features optional except a sleek core. This is what OSGi is trying to do for Java. Unfortunately for the current debate, this is often called a "microkernel" approach. I'm not going to touch that one with a ten foot pole, but let's just say that hopefully Linux can be incrementally rearchitected to make more and more features optional without losing the benefits of its very successful "macrokernel" approach. After all, Linux is already designed to make most of its code optional via the module systems. The only problem is that its core is becoming not-so-sleek, and they're probably already getting as much mileage out of the module system as they can hope for. One interesting possibility is that Linux could avoid the performance hit of run-time dynamism by introducing a new kind of compile-time feature selection. It's obvious to me that C isn't up to the task, but it might not be obvious to someone much smarter than me. Or maybe they could extend C. These days we think of the Linux kernel community as old, conservative, and unlikely to surprise, but who knows? I'll keep my fingers crossed.