Freedcamp

Freedcamp is a budget-friendly project management suite offering an impressive range of features on its free plan, which includes unlimited users, projects, and tasks. Core modules include task management, milestones, calendars, and wikis. Paid upgrades add time tracking, invoicing, Gantt charts, and CRM. Its philosophy is to provide a solid base for free and let teams pay for advanced modules as needed.

It scores well for bootstrapped agencies, freelancers, or small teams needing a capable, no-cost starting point with the option to scale functionality incrementally without a high per-user fee structure.