Here are the new breaking changes in browserify v4. Most users should be unaffected.

# readable-stream

`require('stream')` is now using [readable-stream](https://npmjs.org/package/readable-stream) (but the classic-mode shim persists in stream-browserify just like in node core). This should result in much smaller files for all modules using a similar-enough version of readable-stream as browserify itself. Other modules should be relatively unaffected.

# removed .expose()

Removal of the previously-deprecated and obscure `bundle.expose()`.

# took out implicit reading from stdin

Previously if you invoked the browserify command without any entry files as arguments and stdin was a tty, stdin would be implicitly added as an entry file. This feature was causing problems so it has been removed. https://github.com/substack/node-browserify/issues/724#issuecomment-42731877

# more!

In the run-up to the 4.0, [module-deps](https://npmjs.org/package/module-deps) got an extensive rewrite with minimal test changes. Mostly it was just getting really messy because it was a giant ball-of-mud closure instead of a more straightforward prototype-based implementation with more clearly-defined methods.

The module-deps rewrite was triggered by [system paths showing up in build output](https://github.com/substack/node-browserify/issues/675) but was fixed in 3.46.1. The solution actually didn't end up needing changes in module-deps as originally anticipated but module-deps was in dire need of a cleanup.
