temporal experiment no. 1985

rr-dash

Your program already ran. Go back and watch it happen.

Hit Run and your code is compiled and recorded under rr in a sandboxed machine. Then scrub, step, and replay every line that ever fired — hit counts, call stacks, watch values, the works. Where we're going, we don't need breakpoints.

Destination timeany line that ever ran
Present timethe playhead · live
Last time departedfn main() · tick 0

Full-throttle recording

One click compiles your Rust, C, C++, or Go and records the whole execution under rr on real hardware perf counters. Deterministic, replayable, no plutonium required.

Flux-capacitor timeline

The trace streams in live while it's still being extracted. Scrub the timeline, zoom the flamechart, and jump to any event — forward or backward. It's what makes time travel possible.

Great Scott, watch values

Locals and call stacks are sampled at every single step. Step a line, watch the variables move — exactly the state your program had at that instant in history.