This stack sees a lot of changes. I can see opentelemetry mentioned as next step. Is the overaching goal to produce a spec and reference implementation that could replace ApplicationInsights from Microsoft? Can someone with more knowledge about one or the other chime in with their insights?

The aim with both projects (OpenCensus/OpenTelemetry) is the same: having a open source implementation where you can change the exporter (to GCP,AWS,Zipkin,Jeager or anything you want) whenever you like. So Microsoft (or someone else having the API to report data to Azure) could totally implement an exporter for ApplicationInsights. Both projects have a specs [0][1] that are implemented in multiples languages.

Note: OpenTelemetry is just the project that resulted from the merging of OpenTracing and OpenCensus.

[0] https://github.com/census-instrumentation/opencensus-specs [1] https://github.com/open-telemetry/opentelemetry-specificatio...