Operating Systems
Compare OS architectures, syscall mechanisms, boot processes, and security models across Linux, Windows, and macOS.
Recommended Prerequisites
These are recommendations - you can start this track at any time.
About this track
Compare OS architectures, syscall mechanisms, boot processes, and security models across Linux, Windows, and macOS.
The Operating Systems track collects 4 modules and 16 lessons into a single ordered path. Each module ends with a checkpoint quiz; passing the checkpoint unlocks the next module so you can track your progress without guessing whether the material has stuck.
You start with "Operating System Fundamentals Compared" and finish on "macOS & BSD Internals". The whole track sits inside the Systems Deep Dives area of the curriculum, so the writing assumes the prerequisites listed above and skips ground that an earlier track has already covered.
What this track covers
- Operating System Fundamentals Compared — Compare kernel architectures, process models, memory management, and filesystem designs across Linux, Windows, and macOS to understand the trade-offs each OS makes.
- System Calls Across Operating Systems — Compare how Linux, Windows, and macOS transition from user mode to kernel mode, and examine the syscall interfaces for processes, memory, files, and IPC on each platform.
- Linux vs Windows Internals Compared — Compare boot processes, driver models, security architectures, and networking stacks between Linux and Windows to understand how each OS makes fundamentally different design choices.
- macOS & BSD Internals — Explore the XNU kernel architecture combining Mach and BSD, macOS security features like SIP and Gatekeeper, APFS internals, and the BSD heritage that shaped both macOS and FreeBSD.
How the track works
Every lesson is a short page with diagrams, runnable examples, and the kind of edge-case footnotes you usually only find in textbooks. Where it makes sense, the lesson is paired with a CPU simulation or a coding challenge so you can poke at the idea instead of just reading about it.
The lessons themselves are free to read with a free account. The 4 checkpoint quizzes that gate the next module are also free, as are the lesson IDE and CPU simulations. Optional 777-tier tools — the step-through debugger, decompiler, ROP gadget builder, heap visualiser, and exploit labs — sit alongside the lessons but are not required to follow the track from start to finish.
You can jump in at any point. Be Bitwise is built around a free forever curriculum, with no time limits and no expiring access. Pick the next lesson when you have an hour; come back when you do not.