iPi

iPi is a tiny and portable application you can use to calculate the value of pi. It uses the 4(1-1/3+1/5-1/7...+1/(2n-1)-1/(2n+1)) formula and contains a couple of practical configuration options that can be easily figured out.

The entire program's wrapped in a single .exe file that you can drop to a preferred directory on the disk or copy to a USB flash drive, in order to seamlessly run the app on any computer with minimum effort and no previous experience.

It doesn't change your system registry settings, need DLLs to run, or create files on the disk without asking for your permission. Plus, it's cross-platform and the Mac OS X edition is also included in the downloaded package for Windows.

iPi is packed in a plain interface made from a standard window with a simple design, where you can adjust the calculation speed by moving a slider, specify the frequency for displaying results (number of calculations), and keep an eye on the pi value computed up until that point.

It's possible to pause or restart the calculator, as well as to find out elapsed time, the last computed calculations, and the number of total calculations. Moreover, you can save the progress to file to resume calculations at a later time, or copy the pi value to the Clipboard after selecting the numbers. Keyboard shortcuts are supported for all these commands.

It didn't hog system resources in our tests, since it needed low CPU and RAM to run pi calculations. We haven't come across any unpleasant surprises as far as stability is concerned, since it didn't freeze, crash or indicate errors.

IPi offers a straightforward solution for calculating the value of pi, providing you with useful options for setting the speed and other aspects.