Downloading XICalc 3.2.21 from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. We recommend checking the downloaded files with any free antivirus.
The software lies within Education Tools, more precisely Science Tools. Commonly, this program's installer has the following filename: XICalc.exe. This free program is a product of Harry J. Smith, Private individual. The most popular versions among the program users are 3.2 and 2.1.
From the developer:
XiCalc is a scientific calculator, which evaluates a wide range of different expressions and supports standard mathematical functions. Additional functions and constants can be defined by the user.
XICalc is a small Extra Precision Integer Calculator. It can compute with integers of millions of digit each.
You may want to check out more software, such as Rhythm & Bio, Maxima and Minima or DAC Express, which might be similar to XICalc.