Open source task management alternatives

I’ve used Asana for several years. What are good alternatives that would match its functionality?

I also just discovered Open Project on Nextcloud’s app store as an alternative to Asana, but does anyone have experience using it for a small business and personal use? Does it run on a desktop Linux system or would it need it’s own dedicated machine?

@dotedus that is an excellent question and I cannot believe that no one answered. @vasileios do you have any experience with this kind of software?