Thank you so much for this helpful information! We use Redmine, but I will be exploring other options.
'Gratipay is cultivating an economy of gratitude, generosity, and love, where intrinsic motivation is the norm, and open organizations provide opportunities for everyone to participate in meaningful communities of work.'
Such an interesting read. I've never heard of gratipay either, but my interest is peaked. I love that statement quoted above. It is ideal!