Visopsys

Source

Visopsys (VISual OPerating SYStem) is an alternative operating system for PC-compatible computers, written "from scratch", and developed primarily by a single hobbyist programmer since late 1997.

Visopsys is free software and the source code is available under the terms of the GNU General Public License.  The libraries and header files are licensed under the terms of the GNU Lesser General Public License.

The bulk of Visopsys is a fully multitasking, 100% protected mode, virtual-memory, massively-monolithic-style kernel.  Added to this is a bare-bones C library and a minimal suite of applications — together comprising a small but reasonably functional operating system which can operate natively in either graphical or text modes.  Though it's been in continuous development for a number of years, realistically the target audience remains limited to operating system enthusiasts, students, and assorted other sensation seekers.  The ISO and floppy images available from the download page can install the system, or operate in 'live demo' mode.