JavaScript in the browser runs many times faster than it did two decades ago. And that happened because the browser vendors spent that time working on intensive performance optimizations.
サムネがかわいいwheeeeee
kalk - A flexible calculator that supports variables and functions defined by the user
Kalk is a calculator that supports user-defined variables, functions, ambiguous syntax, derivation and integration. It runs on Windows, macOS, Linux, Android, and in web browsers (with WebAssembly).