As with a number of other software tools, it looks like the better ones are now only web-based.
The standalone apps almost all suck. MS Project is not bad, but it's kinda expensive, and I have other reasons for not wanting to use it - I have in the past and don't want to anymore.
I've now tried RationalPlan, and while it's simple enough and has the basic functions that I need, and is not expensive, its UI is all in all pretty bad. The worse being the quality of the "reports" - they are ugly and almost unusable for any occasion where you'd need to share them.
The open-source ones are kinda the same or worse. GanttProject, ProjectLibre, they do have OK functionalities, but their UI is horrible and the reports are crap.
There is OpenProject which looks rather good (
https://www.openproject.org ) and is open-source. It is web-based, but you can install it on your own server and there is a community edition free to use. Installation is a bit inconvenient though. Then there is OnePoint Projects, which seems kinda in the same league. (Have used it in the past, and they used to have a standalone app version, but it's gone forever.)
Are standalone desktop apps dead already?