This is the best free tool for slope stability analysis. Solute to the developers! Currently the FOS is calculated only on circular slip surfaces. If the developers can add an option to allow users to pre-determine a slip surface and calculate the FOS on that designated surface, that will make this tool have the same capabilities as Slope/W which is a commercial tool and is so expensive that an individual can hardly afford it.   

Hi, it?s been a while since I began working on the non-circular surface failure calculation using a genetic algorithm search. Unfortunately, it?s not quite ready yet. When it?s complete, I?ll release the new version.