My kernel is a 64-bit microkernel. Currently, it's in full re-write. It is not built to be POSIX, but I plan to include some features that make POSIX-style operation and implementation of a usermode POSIX emulation library easier.
The kernel handles memory management, scheduling of threads (1:1 kernel threading), device detection and resource allocation (including interrupts), and IPC. It also makes minor use of detection routines for ACPI / MP table parsing to find SMP information. The kernel will eventually use a text-based configuration file (as a boot module) to allow the user to reconfigure some important settings.
At the moment, I'm re-writing the kernel from scratch.