Yes. It is open-source and MIT licenced. However, nothing is free in life and funding is welcome :-).
Most admin panel are bloated. Admini gives you a minimalistic approach but with a lot of powerful features. It's built using simple build processes (es6 classes, scss) and you can easily fit it within your own build processes (or use the one provided).
- Lightweight JS stack (< 200kb)
- Careful selection of scripts
- Smart tabs (fully responsive with deep linking support)
- A clean and simple user interface