EasyPlot

With most graphing programs, data goes into a spreadsheet and is then graphed. To change a value or edit the graph, you have to go back to the table. EasyPlot is different? It lets you work directly with graphs. To change a value, pick it up and move it. If you want to take a closer look, sketch a rectangle around an area of interest and EasyPlot zooms you in, complete with updated axis labels. It's so logical you'll wonder why other programs don't work this way.