OpalCalc is described as «brand new type of calculator for the PC. As easy to use as Notepad or a word processor, OpalCalc allows natural language in the sum and multi-line support so you can go back and adjust your previous calculations on the fly» and is a Calculator in the education & reference category. There are more than 25 alternatives to OpalCalc for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Android. The best alternative is SpeedCrunch, which is both free and Open Source. Other great apps like OpalCalc are Qalculate!, Numi, Windows Calculator and Soulver.OpalCalc alternatives are mainly Calculators but may also be Note-taking Tools. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of OpalCalc.
