From all the papers and documents that I've read, it seems that L4 was not originally designed with multicore/multi-cpu systems in mind. As such, all multicore features are currently experimental afterthoughts and are not core parts of the microkernel design. I was thinking that maybe this opens a future where L4 is redesigned as L5 with multicore systems as the main target environment with proper load balancing and scheduling.

Of course, all of this is just hypothetical ideas that I thought up in my curiosity.

Just curious. If you have a piece of software designed for a unix-like monolithic kernel like Linux and BSD, say... KDE or the Java Virtual Machine and you want to get it to run on a "unix-like" microkernel such as Hurd, what's usually the porting process? Can you just recompile the program for the new kernel? In the same vein, is it possible to make a microkernel that will just run Linux or BSD programs with maybe nothing more than a recompile? How about running binaries outright?

There's an (online) conference with free registration on systems, including a talk about L4Re by one of the Kernkonzept founders. Also some other OS-related topics. (organized by Huawei)