RxJS version: 6.2.0

The package is more than 6 MB. That is a lot for a utility library.

Why is src included in the package? Source maps and TS definition files are already included for each JS file, so I don't see the need to include the TS source files too.

There's also a lot of bloat related to browser support: bundles, _esm5, _esm2015 (3.8 MB in total). Would you consider publishing a separate package for Node.js usage without all the bloat? For example, rxjs-node.