MarkF from the Azure team. Dapr is not a service mesh, however it will work with service meshes such as itsio, linkerd etc. Dapr does provide direct service-to-service invocation which you can use in place of a service mesh if you want, however Dapr does not handle network policies or traffic management that service meshes do. Dapr is a side-car that is language agnostic, and using http or gRPC provides distributed system building blocks via open APIs for asynchronous pub-sub, stateful services, service discovery and invocation, actors and distributed tracing. All of this is extensible, so you can add new building block capabilities and only choose the use the ones you care about.
The sidecar pattern is shared by a service mesh, so I understand the comparison. However Dapr is focused on enabling in-IDE experiences versus intercepting and proxying networking traffic like a service mesh.
