The software is in pre-alpha development stage. Having prototyped the basic architectural pieces to prove its utility, we are focused on documenting and consolidating things, so that we can better enable the Aegir community to participate in the project.
Aegir 5 is in open development at https://gitlab.com/aegir/aegir. This roadmap will be regularly updated as we iterate, to reflect current progress and status.
We are currently engaged in an agile estimation & planning cycle, in an effort to reboot Aegir5 development in the open.