OpenCalc is a text-based calculator which unlike spreadsheet programs, uses formulas based on a text write-up which are completely human readable.
Unlike other programs in the calculators category, OpenCalc is more intuitive than other programs. It includes a long list of built-in functions .
The interface of this calculator includes two panes. The left-hand side allows for user input while the right-hand side displays the calculations in real time.
While a simple calculation like “10-5” will result in “5”, OpenCalc can also deal with extremely complex formulae.
The program is restricted freeware, but a donation to the coder removes the 5 line limit.