I've been busy the last few months participating on a new open source operating system called SharpOS. What makes SharpOS interesting is that is an operating system written almost entirely in C# that provides a Common Language Runtime (CLR) managed environment for applications to run.
What is truly interesting about this type of operating system is that all applications and nearly all of the kernel code will run in a managed environment; meaning there are no memory pointers or explicit memory allocations. A managed environment enforces that applications are verifiably safe.
Since the team reach their first milestone earlier this year -- a proof-of-concept implementation with an interactive diagnostics shell, I have actively working on the Floppy Disk and IDE device drivers, FAT file system support, and integration with the Virtual File System (VFS) framework developed by Michael Ruck (aka grover).
Expect more news about SharpOS in the future!