Angular's new offline compiler was demo'ed at ng-conf day 2 keynote by @robwormald. It generates tree-shakable ES6 code. Four steps are then required: run a tree-shaker to remove ES6 modules not reachable from the entry point, in our demo we showed rollup run a bundler to reduce down the module imports into a declarations in a single file; we showed system.js down-level to ES5 - we showed this wit