Really depend what you have in mind with "project management".

If it really means "Microsoft Project without paying license", maybe GanttProject[1] is what you need.

If you want something that helps you and your team to manage your project from requirements to delivery and maintenance, you can have a look at Tuleap[2] (I'm part of dev team).

You can do the project management still of your own (waterfall, scrum, kanban, hybrid). If you are doing software development, it comes with git, gerrit, subversion native. It's a full featured ALM so it provides everything you need (documentation management, wiki, forums, IM, test mgmt, ...) without having to maintain N stack of incompatible tools with incompatible plugins & all.

[1] http://www.ganttproject.biz/ [2] https://tuleap.org

Seems https://taiga.io/ is open-sourced and pretty good, made with python and angular

I think you'd need to define "good" to get a usable answer to this question. What features are you looking for? How many people will be using it? Have you looked at anything already? If so, what did you like/not like about them?

That said, check out Redmine and Tiaga and possibly Kanboard.

Like everyone else says, "good" is a state of mind. For my exceedingly meagre needs I find GNOME's "Planner" to be, at the very least, a good way of knocking up Gantt charts quickly.

I really like redmine.org, though the UI is terrible. Can be themed!