GTMOS

A hobby UNIX-like OS with a graphical window manager for x86 computers.

Booting off of the primary master IDE (PATA) hard drive on both emulators and real hardware (tested on a Dell Optiplex 320 with a Pentium D)
PATA DMA or PIO access (force PIO by using the use_pio grub kernel argument)
A virtual filesystem with device files (/dev/hda, /dev/zero, /dev/random, /dev/fb, /dev/tty, etc)
- The root filesystem is ext2, and is writeable
Disk caching
Dynamic linking with shared libraries
A Bochs/Qemu/VirtualBox/Multiboot video driver (640x480x32bpp)
A window manager / compositor called pond
Various GUI applications
More!

The code for these can be found in services.

The code for these can be found in programs

Calculator (/apps/calculator.app): A basic calculator.
Terminal (/apps/terminal.app): A libui-based terminal application.
System Monitor (/apps/monitor.app): A basic system monitor showing memory and CPU utilization.
4 In a Row (/apps/4inarow.app): A basic four-in-a-row game. Play with two players or against the computer.
Sandbar (/bin/sandbar): A basic "taskbar" that displays a row of buttons at the bottom of the screen to launch applications.
Files (/apps/files.app): A rudimentary file explorer application.

The code for these can be found in programs.

ls (/bin/ls): Lists the entries in the current or given directory.
cat (/bin/cat): Writes the contents of a file to stdout.
cp (/bin/cp): Copies a file.
mv (/bin/mv): Moves a file.
pwd (/bin/pwd): Prints the current working directory.
mkdir (/bin/mkdir): Creates a new directory.
echo (/bin/echo): Prints the arguments given to it separated by spaces to stdout.
rm (/bin/rm): Removes a file.
ln (/bin/ln): Creates a hard or symbolic link to a file or directory.
rmdir (/bin/rmdir): Removes a directory.
touch (/bin/touch): Updates the access/modification times of a file or creates it if it doesn't exist.
truncate (/bin/truncate): Resizes a file.
chmod (/bin/chmod): Changes the mode of a file.
chown (/bin/chown): Changes the owner of a file.
free (/bin/free): Shows the amount of total, used, and free memory (use the -h flag for human-readable numbers).
ps (/bin/ps): Shows the currently running processes.
dsh (/bin/dsh): A basic userspace shell with support for pipes (|) and redirections (>/>>).
- There is only support for one redirection at a time right now.
apprun (/bin/apprun): A utility to run applications from the command line.

Programs that take arguments will provide you with the correct usage when you run them without arguments.

libc: The standard C library.
libm: The math portion of the standard C library.
libpond: The library used for interfacing with the pond window manager / compositor.
libgraphics: A library which provides a few utilities for working with graphics such as image format loading.
libui: A UI framework for applications.
libterm: A framework for handling terminals.
libduck: A library containing commonly used classes and utilities, such as argument and configuration file parsing.
libriver: An IPC library not dissimilar to D-Bus, which provides a framework for remote function calls and data passing.
libapp: A library providing methods to retrieve information about installed and running applications.
libsys: Provides higher-level C++ abstractions for retrieving system information, namely from procFS.

Ports will only compile if their corresponding submodule is downloaded with git submodule init and git submodule update.

DOOM: A little buggy at the moment, but playable. With the current multitasking and window manager implementation, it can be a little slow.

Framebuffer scrolling is slow on real hardware. I'm not focusing on fixing this right now until I start working on a window manager.
Must be booted off of the master drive on the primary PATA controller as of now.
Ext2 triply indirect block pointers cannot be read/written, so there may be issues writing and reading large files
A buffer overflow attack on the kernel may be possible, because only pointers passed to syscalls are checked for validity (and not the length of the data to be read/written)
Dynamic linking does not currently use CoW to share memory between processes, so each process has its own copy of the library in memory
It's pretty unstable

Cut down on memory usage by sharing memory for various commonly used items (libraries, icons, configuration, etc)
Better support for real hardware
Network support
Sound support
More s t a b i l i t y and s p e e d
Multiprocessor (multicore) support
An in-house heap implementation
More POSIX compatibility
Better looking UI with animations and effects such as shadows and blur/transparency
Slowly transition various functions from the kernel to userspace (ie microkernel)
A better filesystem cache implementation that can free memory when needed and periodically flushes writes

blanham's mirror of liballoc 1.1 for the kernel heap allocation implementation (it's open domain, so if you want to use it, I highly recommend it)
SRombaut's implementation of shared_ptr
SerenityOS for a lot of inspiration
Gohufont for the font (licensed under WTFPL)

ajh123-archives / duckOS