Sente

Sente was once a highly regarded reference manager for macOS and iPad, known for its beautiful interface and innovative approach to research management. It offered excellent PDF annotation and a unique way to organize references. However, development has largely ceased, and it is no longer actively supported or updated. While it still functions for some users, it is not recommended for new projects due to compatibility issues with modern operating systems and the lack of security updates.

It remains a nostalgic favorite for long-time users who appreciated its design.