# TacOS: A Hobbyist OS Kernel Springs to Life, Runs Doom!

## TacOS: A Hobbyist OS Kernel Springs to Life, Runs Doom!

The open-source community is abuzz with a fascinating “Show HN” project: TacOS, a from-scratch operating system kernel that can actually run Doom. Developed by GitHub user “UnmappedStack,” TacOS is a testament to the dedication and skill of hobbyist OS developers, proving that complex systems can be built from the ground up by individual programmers.

According to the project’s post, TacOS has been in development on and off for several months. It leverages familiar UNIX-derived concepts like `exec/fork` and a UNIX-style Virtual File System (VFS). This foundation allowed the developer to port Doom, the iconic first-person shooter, with a surprisingly small number of modifications. Notably, this feat was achieved using a custom-built C standard library (libc), showcasing the breadth of skills required for such an undertaking.

The real surprise, according to UnmappedStack, is the performance. Describing it as “decent compared to what I expected,” this suggests that TacOS is more than just a proof-of-concept; it’s a functional operating system capable of delivering a playable experience.

This project offers several intriguing takeaways. Firstly, it highlights the enduring appeal of operating system development as a hobby. Building a kernel from scratch is a significant undertaking, requiring a deep understanding of computer architecture, memory management, and system calls. TacOS serves as a great example of how individuals can contribute to the understanding and advancement of operating system technology.

Secondly, the decision to use UNIX-derived concepts demonstrates the value of established paradigms. By building on existing models, UnmappedStack was able to leverage existing knowledge and tools, streamlining the development process. The use of a custom libc also speaks to a level of control and optimization rarely seen in modern operating systems.

Finally, the fact that Doom runs on TacOS is a powerful and evocative demonstration of its capabilities. Doom has long been used as a benchmark for system performance and a target for porting efforts, making it the perfect showcase for the project.

For those interested in exploring the project further, the source code is available on GitHub at [https://github.com/UnmappedStack/TacOS](https://github.com/UnmappedStack/TacOS). The project’s creator welcomes feedback and discussion, making it an excellent opportunity to learn from and contribute to the world of operating system development. TacOS stands as a fascinating example of what can be achieved with passion, dedication, and a solid understanding of the underlying principles of operating systems.