APCalc stands for Adjustable Precision Calculator. The initial precision is 1000 decimal digits. Numbers are displayed in scientific notation. Exponents are indicated with a very cool drop 10 symbol inherited from ALGOL (Decimal Exponent Symbol U+23E8 TTF). Coding was done in C++ on Linux with library gtkmm-3.0 The widgets were GTK Gnome Tool Kit widgets set up with Glade.