The main competitor for Jaeger is Zipkin. It's an older project, which also means it is more mature. Usually, more senior projects are also better supported, but in this case, the endorsement of CNCF plays in Jaeger's favor.
Zipkin uses its proprietary protocol to handle tracing. It has OpenTracing support available, but it may not be at the same maturity and support level as the native Jaeger protocol. As we've mentioned earlier, it is also possible to configure Jaeger to collect traces in Zipkin format. This means the two are, at least to some point, interchangeable.
The project is hosted under the Apache foundation, but is not considered a CNCF project. When developing cloud-native applications, Jaeger is a better alternative. If you are looking instead for an all-purpose tracing solution, it is worth considering Zipkin as well.
One drawback is that Zipkin doesn't have a supported C++ implementation. There are unofficial libraries, but they don't seem...
