Details matter, but without anything else to go on, I'd consider an open source projects, then sell a professionally managed service that makes it easy for cust

Details matter, but without anything else to go on, I'd consider an open source projects, then sell a professionally managed service that makes it easy for customers to use. Of course include backups, patching, and support as part of the management. Projects like Piwigo (image editing, organizing and hosting) and SchedMD/Slurm are good examples. Generally it's MUCH easier to budget based on subscriptions, then playing the prediction game for which users will pay $x for feature Y.