WolframAlpha         eccellente per il calcolo simbolico (e non solo)
 

                                       Geogebra            algebra-geometria-analisi

                                                     QBasic                 EXE  tutorial      Prog
                                   
                                            Dev-Pascal          EXE                                       
                                                                                                    
                                             WxMaxima        calcolo simbolico  (offline)                                                                                                                                                                                                   
                                             WIMS                     calcolo on line