PsySH - A runtime developer console, interactive debugger and REPL for PHP.
Calculist - The open-source, web-based thinking tool that facilitates effective thinking for solving problems.
Jupyter - Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages. Ready to get started? Try it in your browser Install the Notebook.
Numi App - Numi is a beautiful text calculator for Mac.
RunKit - RunKit notebooks are interactive javascript playgrounds connected to a complete node environment right in your browser. Every npm module pre-installed.
Soulver - Soulver is a software application that functions as a calculator that allows you type a continuous stream of information rather than having to input data into multiple cells.