I am using weka algorithim by knime work flow to predict survaival test , and I have API
which send the data to knime and than I get the result. is that ligal to use it for Commercial reasons for the campany ? should my campany pay to weka or to knime because we have to this tools?
Paying for a tool is not something you do because you have to, but something you do because you recognize its value and want to sustain its long term usefulness.
That said, I want to help you, but I don't want to give you legal advice as I'm not a lawyer. But my tip is to speak to one about this. Both Weka and Knime have "standard" licenses as far as I understand it, so he should be able to give you clear answers that apply both to your particular use case and to your local laws.