Beside its simple calculation ability ( Add- Subtract  - Multiply -
Division -  Sqr - Percentage ) functions it has the following features
as a Metric Calculator too

• Length Metric Converter
• Area Metric Converter
• Volumes Metric Converter
• Weights Metric Converter
• Liquid Metric Converter
• Temperature Metric Converter

• Gnu compatible C compiler ( Cgywin - https://www.cygwin.com/ )
• Gtk+ 3.0 UI ( https://www.gtk.org/download/windows.php )

After download and unzip , navigate to the extracted folder and run the following command:

gcc main.c -o calc.exe `pkg-config --cflags --libs gtk+-3.0`

For more in detail installation and compile instruction please read the instillation.txt included file