I am writing a small memoryprint operating system (now 5.2Kb) called ados, the code is at http://github.com/v-zor/ados

To try it out, run make in the ados/kernel subdirectory to compile then use QEMU (https://www.qemu.org/, with the following command : 'qemu-system-i386 -kernel kernel.bin' (kernel.bin is made with the make command.)
Then you'll see the kernel.bin binary booting and the kernel goes idle.

You can also make a CDROM/DVDROM iso file with the mkgrubiso.sh script in the ados/scripts directory then burn it and boot it with the cd in the drive.

TODO and further HACKING :
I am working on a bootloader, task management system and disk master boot record program, see for your self in the HACKING and README files in the project. Maybe later there's lots of other things planned as I want to use it for embedded devices with serial ports and so on.