Understand licensing, support, updates and sustainability without needing to read source code.
Open source describes rights, not polish
The licence may allow inspection, modification and redistribution, but projects vary widely in usability, documentation and support. Judge the actual project and community.
Look for signs of maintenance
Recent releases, responsive issue handling, security guidance and multiple active contributors indicate resilience. A popular name alone does not guarantee healthy maintenance.
Choose a support model
Individuals may rely on community documentation, while organizations often need paid support or an experienced internal owner. The software can be free to acquire without being free to operate.