No d3 global is exported if AMD or CommonJS is detected.

Another solution is using the Safe Navigation Operator &. introduced in Ruby 2.3 which is a bit better because this is a language feature rather than an opinionated runtime environment pollution

Internal Sass features have also moved into the module system, so we have complete control over the global namespace.

// Use `noConflict` to restore the pre-fp variant. var fp = _.noConflict();

Polyfills are naughty as they patch native APIs, while ponyfills are pure and don't affect the environment.

How are ponyfills better than polyfills? A polyfill is code that adds missing functionality by monkey patching an API. Unfortunately, it usually globally patches built-ins, which affects all code running in the environment. This is especially problematic when a polyfill is not fully spec compliant (which in some cases is impossible), as it could cause very hard to debug bugs and inconsistencies. Or when the spec for a new feature changes and your code depends on behavior that a module somewhere else in the dependency tree polyfills differently. In general, you should not modify API's you don't own.

protect against polluting the global environment