You could have downloaded PowderPlot 2.0.1 for Mac from our application library for free. The actual developer of this free software for Mac is Geocities. The most popular versions among the application users are 2.0 and 0.3. PowderPlot for Mac is included in Education Tools.
From the developer:
Stand alone Java program to show RIETAN-2000's powder pattern out put files(*.pat).
PowderPlot can display *.pat files and *.int files.
You can zoom patterns by dragging the plot area where you want to see. Double click to show whole pattern. On "move" mode, you can drag graph area
You may want to check out more Mac applications, such as iRNAi, Gee or NLVM, which might be related to PowderPlot.