Lplanner is a decompression planner for trained mixed-gas divers. It plans open-circuit and closed-circuit dives on air, nitrox, trimix and heliox, with three decompression models to choose between. THIS SOFTWARE CAN KILL YOU. It is experimental and certainly contains bugs. Never dive a schedule from it without verifying that schedule against tables or software you trust, and never use it without formal mixed-gas decompression training. MODELS * ZHL-16C — the Buhlmann set, with gradient factors or a conservatism percentage, and optional Pyle deep stops. * VVAL-79 — the U.S. Navy Thalmann EL-DCM, exponential uptake and linear elimination, with the published nine-compartment air parameter set. Air, nitrox and oxygen only: the Navy publishes no helium parameters for this model, so a dive carrying helium is refused rather than computed against numbers that do not exist. Use VPM-B or ZHL-16C for trimix. * VPM-B — the Varying Permeability Model of Yount and Hoffman, in Erik Baker's implementation, with conservatism 0 to 4. Checked against Baker's own published output on his 80 msw trimix benchmark: 13 of the 18 stop times match exactly, with the first stop one 3 m increment deeper and four minutes more total stop time, for the reasons set out in the manual. All three share one decompression engine, written in C, which is the same engine the macOS and iOS builds use. Identical input gives an identical schedule on every platform. WHAT IT DOES * Multi-level dives, open or closed circuit, with setpoints and Scamahorn slide. * Automatic deco gas selection by maximum PO2 and maximum END. * Repetitive dives: carries your tissue loading forward, ages it against the real clock while the app is closed, and requires you to state a surface interval before it will plan again. * CNS percentage and OTU tracking, gas consumption per mix, time to fly. * Gas density warning following Anthony and Mitchell. * Configurable stop grid, last stop depth, ascent and d