Project still maintained?

I got to this project following the Google documentation about Binary Authorization:
https://cloud.google.com/binary-authorization/docs/creating-attestations-voucher

They mention two options for security vulnerability attestations, Kritis and Voucher.
I noticed that Kritis might not be maintained anymore (grafeas/kritis#632)

Is Voucher is still maintained?

The README of this project mentions: "Binary authorization uses an admission controller such as Kritis", does Voucher use Kritis?, or are these totally separate?

[thepwagner]

Per https://github.com/shopify/voucher being archived, Shopify is no longer using voucher or involved in this repository.
Most, but not all, contributors have been from Shopify: https://github.com/grafeas/voucher/graphs/contributors
We defer a decision about official deprecation to our partners in Google Cloud (e.g. @ooq, _rhdesmond et al).

Shopify replaced Voucher with a system that wraps https://github.com/kyverno/kyverno/ policies to produce binary authorization attestations. We like how other admission controllers provide a general "policy" abstraction for us, so we shifted to wrapping an admission controller to produce our binauthz attestations.
We like how this prevents coupling to GKE - we could run the same policies using Kyverno directly as an admission controller.

Our new system is not open source, sorry.