OpenProject

OpenProject is a mature, open-source project management platform emphasizing Gantt charts, resource planning, and comprehensive reporting—ideal for teams managing complex, interdependent projects. Its free Community edition (on-premises) includes all core features with community support, while cloud and on-premises Enterprise editions ($5.95–€19.50/user/month) unlock professional support, advanced workflows, and plugin compatibility. For indie hackers and small teams, the free Community version is fully functional; scaling to paid tiers is optional and gradual.\n\nOpenProject excels at construction, manufacturing, and operations teams that require detailed timelines and resource allocation. For indie hackers and startups, it's a solid alternative to Jira if you need Gantt charts without Jira's complexity. The platform has been around since 2012, ensuring stability and a mature codebase. Trade-offs: the UI is more enterprise-oriented than modern tools like Linear or Plane, and the learning curve is steeper. If your team needs waterfall-style project planning with extensive customization, OpenProject is the best free alternative. If you need agile sprints and developer speed, Linear or Plane are better bets.