OpalCalc is new type of calculator using natural language to function like Notepad or a word processor. It lets you build text with numbers adjacent to sums over multiple lines so you can quickly go back and adjust your previous calculations with the answers auto-updating on the fly. OpalCalc is ideal for putting math into everyday thinking such as for quick budgets and shopping lists.
Built-in features include percentages, currency conversion, custom functions/variables, date/time support, color coding, lightweight size, configurable interface, hundreds of measures and functions, and more.
Freeware version limited to 5 lines.