KernelPath vs ControlsLab

KernelPath is a comprehensive, interactive course on operating system kernels — built entirely for iPad and iPhone. GO FROM ZERO TO KERNEL FLUENT Work through 7 structured modules covering the full Linux kernel stack: architecture, processes, memory, file systems, networking, security, and device drivers. Each lesson combines clear explanations with real C code examples, diagrams, and practical command-line usage. LEARN BY DOING 14 interactive labs let you visualize concepts that textbooks struggle to explain: - Step through the boot sequence from BIOS to login - Watch the CFS scheduler assign CPU time to competing processes - Walk a page table translation from virtual to physical address - Trace a system call from user space into the kernel - Animate a TCP three-way handshake in real time - Build and test seccomp filters on system calls - Follow a read() call from application through the driver stack to hardware PRACTICE IN A REAL TERMINAL A built-in Linux terminal simulator gives you a virtual machine to explore. Navigate a realistic filesystem with /proc, /sys, /dev, and /etc. Run 50+ real commands — ls, ps aux, free -h, ip addr, cat /proc/cpuinfo, lsmod, and many more — all producing authentic Linux output. TEST YOUR KNOWLEDGE Each module ends with a quiz. Detailed explanations for every answer reinforce what you learned and fill in gaps. TRACK YOUR PROGRESS A personal dashboard shows completed lessons, quiz scores, and module-by-module progress so you always know where you left off. WHAT YOU'LL LEARN - Kernel architectures: monolithic, microkernel, and hybrid designs - Process lifecycle: fork(), exec(), scheduling, IPC, and signals - Virtual memory: page tables, the MMU, allocation, and swap - File systems: VFS, ext4 internals, inodes, and permissions - Networking: TCP/IP stack, packet encapsulation, sockets, and netfilter - Security: DAC, capabilities, SELinux, AppArmor, and seccomp - Device drivers: character and block devices, udev, and driver architecture BUILT FOR LEARNERS No prior kernel experience required. Start from "What is a Kernel?" and build up to writing device drivers and configuring seccomp filters. Perfect for computer science students, self-taught developers, SREs, and anyone who wants to understand what happens beneath the surface of every application.

ControlsLab is a professional-grade system dynamics and controls simulator designed for engineering students, educators, and practicing engineers. Simulate a mass-spring-damper system in real time. Adjust parameters with intuitive sliders and instantly see how the system responds - no coding required, no MATLAB license needed. FREE FEATURES SYSTEM SIMULATION - Mass, damping, and spring parameter control - Step, ramp, parabolic, and sinusoidal inputs - Adjustable initial conditions x(0) and dx(0) - Input signal overlay on time response plot VISUALIZATION - Live time-domain response plot - S-plane pole visualization - System stability classification - Overdamped, underdamped, critically damped detection ANALYSIS MODES - Open-loop mode: plant driven directly by input - Closed-loop mode: negative feedback with configurable setpoint PRO FEATURES - $4.99 One-time purchase, no subscription PID CONTROLLER - Full negative feedback implementation - P, PI, PD, and PID controller types - Live Kp, Ki, Kd gain tuning with instant response - Adjustable reference setpoint FREQUENCY DOMAIN - Bode plot: magnitude (dB) and phase (degrees) - Logarithmic frequency axis - Natural frequency, damping ratio, and bandwidth readouts WHO IS THIS FOR? - Undergraduate engineering students studying dynamic systems and feedback control - Graduate students reviewing control theory - Professors and educators demonstrating system behavior in lectures - Practicing engineers doing quick back-of-envelope system analysis - Anyone curious about how control systems work ControlsLab turns abstract differential equations into visual, interactive experiences. Move a slider and watch poles migrate across the S-plane. Toggle a controller and see overshoot disappear in real time. No prior programming experience required.