If you've ever tried building a Manufacturing Execution System (MES) , a production planning tool, or a real-time resource scheduling UI in JavaScript, you know that picking the right library is not the same problem as picking a Gantt chart for project management. A factory floor is not a Trello board. You're dealing with: Hundreds of machines / work centers running in parallel Real-time updates streaming from sensors, MQTT, OPC-UA, or your ERP Shift patterns, exclusion zones, maintenance windows Constraint solving (resource availability, sequencing, setup times) Operators interacting with the schedule on industrial touch screens Most "Gantt chart" libraries collapse under these requirements. The ones that don't are very different beasts. This post compares 7 JavaScript scheduling libraries specifically through the lens of MES, production planning, and resource scheduling — not generic project management. Each library is evaluated against the same 8 criteria , no shortcuts.…