Which starter app kit or cms / admin system to choose?

Thank you for your replies, both.

Could you tell me what is the technology stack you're using?

For example, which authentication system (if any)? Which assets management? And internationalisation?

What about the admin site? Do you use any specific products/CRUD, or do you build one every time your according to your needs?

Or maybe does anyone have a pointer to a documentation/page/thread discussing the library stack?

Thank you
Stefano