We have a framework more than a library, we basically ship a framework that our clients use to create their own web trading applications. This framework covers many asset classes and many use cases.

It's not likely that any client would use all of our code and so we have build a tool framework that only pulls in the JS code that your application uses, this is done without a build and is immediately available (add a 'new namespace.sub.Class()' line and hit f5 and it will be in the js bundle you get.)

We bundle js, css, xml, i18n tokens etc.

All automatic and requiring no build.

Why not?