ProjectLibre is the most popular alternative to Microsoft Project. 4,700,000 downloads in over 200 countries and translated into 25 languages.
ProjectLibre is the only open source solution with a compatible data model with Microsoft Project so you can import even the most detailed project data without error.
ProjectLibre has Gantt Chart, Network Diagram, WBS, RBS, Task Usage, Resource Usage and more
It's easy enough for someone with no previous experience of project management software or even business process automation tools (like this one) - but has all you need if your looking at more advanced functionalities like data analysis etc that would require some coding skills! The interface could be made slightly easier/more intuitive so it feels less 'clunky'.
Also we needed an option where our team members were able use their own log-ins rather than having us set up accounts & passwords…
Pros
Intuitive UI, simple to learn
Excellent customer service via email support& live chat in my particular case
Fast responses during normal working hours(ish)
Multi user system; multiple users accessing same account easily