As interesting as the Mill looks on paper, it's hard to keep faith in this architecture ever coming to fruition with the decreasing press coverage [1] (8 articles in 2013, only 1 each in 2014, 2015, 2017, several about fund seeking) and lack of activity in the Implementation section of their Forum [2] (one nearly 1 year old thread and others nearly 3 years old or more).

[1] https://millcomputing.com/in-the-press/

[2] https://millcomputing.com/forum/the-mill/implementation/