Claudimon

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  VGA text mode driver

  Writes directly to video memory at 0xB8000. 80 by 25 character grid, 16 colour palette, scrolling handled by hand.
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  CMFS, a custom on-disk filesystem

  Backed by a hand written ATA PIO disk driver. Files and directories persist across reboots.
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  Seven keyboard layouts

  UK and US QWERTY, Dvorak, Colemak, Swedish, German (QWERTZ), and French (AZERTY). Switchable at runtime.
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  In-kernel text editor

  A full screen editor with save and quit shortcuts, writing straight to the filesystem.
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  PC speaker driver

  Programs the 8253 PIT directly for tones: boot jingle, error sounds, and a manual play command.
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  Five colour themes

  Classic, Amber, Ice, Hacker, and Rose, switchable live from the shell.
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  Power management

  Shutdown and reboot, using QEMU's ACPI shutdown ports and the classic keyboard controller reset trick.
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  Command history and scrollback recall

  Up and down arrows cycle through the last ten commands typed.

Claudimon is honest about what it does not do. There is no memory protection, so a bug can write to any address including kernel memory itself. There is no user or permission system. Multitasking is not implemented, the shell runs one command at a time. There is no network stack. Disk access uses a single hand rolled filesystem with no journaling, so a power cut mid write can corrupt a file.

See the About page for more on the project's scope and intent.