Maybe you're thinking of the drama involving Caddy putting sponsorships into its Server header. They walked that back relatively quickly and hasn't been a problem since then.
Back when they both were on the rise, they felt equivalent. I haven't deployed Traefik in a long time but as far as I remember, Traefik's configuration is more service-discovery oriented. While they both are capable of working with a static set of hosts, it felt like Traefik made it harder to configure for a static set of upstream servers while Caddy made it much easier. Traefik almost started off with the assumption that you would have some service discovery of some sort.
You are right, Traefik is fundamentally built around the concept of "providers," which are external systems from which Traefik obtains routing configuration and service/server definitions.
These providers can range from dynamic service discovery systems (like Docker, Kubernetes, Consul) to static configuration sources (file-based configs, HTTP APIs, etc.). The provider architecture is what makes Traefik particularly well-suited for containerized and cloud-native environments where services are ephemeral and discovery is crucial.
Ah, I didn't remember that. I've been googling a bit and I think this was it [0]: binaries on their download page or GitHub releases were only usable on a personal basis. If you were to use them in a company, even internally, you needed to get a commercial license or build the binary yourself.
Back when they both were on the rise, they felt equivalent. I haven't deployed Traefik in a long time but as far as I remember, Traefik's configuration is more service-discovery oriented. While they both are capable of working with a static set of hosts, it felt like Traefik made it harder to configure for a static set of upstream servers while Caddy made it much easier. Traefik almost started off with the assumption that you would have some service discovery of some sort.