regexpu-core
regexpu’s core functionality (i.e. `rewritePattern(pattern, flag)`), capable of translating ES6 Unicode regular expressions to ES5.
recast
JavaScript syntax tree transformer, nondestructive pretty-printer, and automatic source map generator
regenerator
Source transformer enabling ECMAScript 6 generator functions (yield) in JavaScript-of-today (ES5)
regexpu
A source code transpiler that enables the use of ES2015 Unicode regular expressions in ES5.