ThreadLab
A browser-based lab where CS students see POSIX concurrency come alive in plain C — mutexes, condition variables, atomics, thread pools, and a Go-style channel — with visualizations and auto-graded labs that don't require installing a toolchain.
Second- and third-year undergraduate CS students taking operating systems or systems programming courses
- In-browser interactive C snippets that visualize lock contention, atomic fast paths, and pool scheduling as they run
- Cover the full arc from the Go-flavored article: mutex/cond, atomics, worker pool, channels — translated line-by-line to plain C
- Step-by-step exercises: build a thread pool, build a channel, debug a data race, with hints that don't give the answer away
- Instructor mode to assign labs to a roster and auto-grade submissions on race-free output and correctness
The 'Go-flavored concurrency in C' article on HN, paired with the ongoing teaching gap of giving students a real pthread experience without a Linux VM, makes a browser-based concurrency lab a natural classroom fit.
HN source article only received 4 points (not 28 as claimed); pthread tutorials (randu.org, Villanova) exist but indicate a persistent teaching gap rather than demonstrated demand for a paid browser lab.Go-Flavored Concurrency in C | Hacker News ↗Multithreaded Programming (POSIX pthreads Tutorial) - randu.org ↗
Crowded with free alternatives: ThreadViz, SpeyTech Race Condition Visualizer, GitHub Race-Condition/Mutex-Visualizer, Go Concurrency Visualiser, and Emscripten's existing pthread-to-WASM tooling already cover much of this ground.ThreadViz - Concurrency Visualization Tool ↗Race Condition Visualizer | SpeyTech ↗aditichauhan2186/Race-Condition-Mutex-Visualizer - GitHub ↗True Multi-Threading in WebAssembly via pthreads | NitroIDE ↗
Student-facing CS learning tools have notoriously weak willingness to pay; no evidence of institutional autograder budgets, and most competitors (ThreadViz, SpeyTech, GitHub projects) are free.ThreadViz - Concurrency Visualization Tool ↗
Concurrency education is a durable curriculum topic (OS courses have taught it for decades), but the specific browser-rendered niche may shift as Wasm standards evolve; mid-to-strong longevity.
Building true pthreads-in-browser is technically proven via Emscripten + SharedArrayBuffer; the heavy lift is sandboxing, multi-user autograding, and pedagogy — feasible but not trivial.Using WebAssembly threads from C, C++ and Rust - web.dev ↗