The following dive planning programs are in the public domain, and we should be very grateful to their generous authors. Feel free to download them, but only use them if you are suitably qualified to do the dive. And please, abide by the conditions set out by the authors.
MV-Planby Guy Wittig.
MV-Plan is a Gradient Factors modified Buhlmann algorithm written in Java and will work on any Java platform (PC, Mac, Linux etc). Guy wrote this especially for those using CCR who want to use Gradient Factors in an easy to use package. The high and low Gradient Factors are user adjustable, and open circuit deco and bailout is available. It can save your dives to an XML database for multiple dive planning. It's got a VPlanner type look and feel to it. This is the one to have!
You must have the Java runtime installed on your machine.
ZPlanV1.03 by Will Smithers
ZPlan is based on the Buhlmann ZH-L16 algorithm. It is capable of Rich Pyle style deep stops and you can also alter your conservatism factor. This is the text based version. I used this program for many years, using 15% conservatism and 2 minute Pyle Stops. It's simple and works great. Thanks Will, and farewell.
DDPlanV2.15 by Gordon Henderson
DDPlan is also based on Buhlmann's ZH-L16 algorithm, but incorporates Erik C. Baker's Gradient Factors to adjust the schedule for deep stops. The high and low Gradient Factors are user adjustable, or they can be bypassed to give a pure Buhlmann schedule. It is a DOS text based program.
GAPV1.22 by Kees Hofwegen
GAP is a Windows version of the Gradient Factors modified Buhlmann algorithm. The high and low Gradient Factors are user adjustable, or they can be bypassed to give a pure Buhlmann schedule. This is like an Abyss style version of DDPlan. This is an old version and is kept here for entertainment value. Once Kees realises it's here, it may be taken off.
ZPlannerV1.01 by Ross Hemmingway
ZPlanner is a Windows interface for ZPlan which is easier for those who like Windows rather than text based. Ross would prefer you buy his V-Planner software and has asked that I no longer offer Z-Planner on my website. Sorry. Of course, the DOS version of ZPlan still does the job, it just doesn't have Ross's Windows interface.
V-Planner by Ross Hemmingway
V-Planner is based on the Varying Permeability Model of Eric C. Baker. It generally gives shorter hang times than most other programs, but gives more and deeper deep stops. (This info may be out of date, as I stopped playing with this program quite some time ago). This program has a Windows interface. From V2.00 onwards, VPlanner is no longer free, but reasonably priced payware.