> Does the solution to your problem have to be free (as in $0), or are you willing to pay? That's a different axis. Solutions need to be open (interoperable)

> Does the solution to your problem have to be free (as in $0), or are you willing to pay? That's a different axis. Solutions need to be open (interoperable) standards. That means I must have the ability to sit down and implement all of it myself and it'll interoperate with everyone else. Whether you pay or not is separate consideration. If I implement everything myself I pay nothing other than a lot of my time. Alternatively I can pay someone else to implement it for me, or buy a pre-built solution from any number of vendors, or subscribe to a SaaS solution from other vendors. The key is interoperability between all these. Like HTTP or SMTP.