registration form in module

How can I display the registration form in a module? It should also display the login form since I set up the configuration like that.

You can't without an iframe. We don't have a registration module. We've plans for one, but it's not going to make it in CB 2.1 release and likely pushed to CB 2.2.

I put the registration page in an iframe. But since the registraiton page loads a few TB of scripts it is very slow. When will the module be available?

But since the registraiton page loads a few TB of scripts it is very slow.

Don't understand what you mean by this. It'll be no slower than visiting the page it self. As long as debug mode is not enabled CB will also always use its minified JS. Ensure you're using &tmpl=component to avoid loading in anything other than the component.

When will the module be available?

No idea; it is not a priority right now.

All major social websites and hotels have a modal window for quick registration and login. Why is CB still hanging on to an outdated process from the 90s? This is getting really frustrating now. Still no plans to implement contemporary code? I can do the styling myself but at least the module must be there.

Registration layout for the CB Login module is already being developed. It's currently under review to be merged then released soon. There won't be another module to install or anything of the sort either. You'd simply create a CB Login module and change its layout parameter.