I'll be looking for an open-source option first today, but if not, I can wholeheartedly recommend the xplorer^2^ from Zakbat. I've been using it for more than 10 years and it's fantastic for me. As far as I know, this is the work of a single guy. It is not cheap, but it has worked extremely well and has been reliable for me for so many years that I can't recommend it enough. It has a free trial to test it.