there's a lot of good questions, and some confusion in this thread. here is my view. note: i'm definitely biased; am the co-founder/ceo at grafana labs.
- at grafana labs we are huge fans of prometheus. it has become the most popular metrics backend for grafana. we view cortex and prometheus as complementary. we are also very active contributors to the prometheus project itself. in fact, cortex vendors in prometheus.
- you can think of cortex as a scale-out, multi-tenant, highly available "implementation" of prometheus itself.
- the reason grafana labs put so much resources into cortex is because it powers our grafana cloud product (which offers a prometheus backend). like grafana itself, we are also actively working on an enterprise edition of cortex that is designed to meet the security and feature requirements of the largest companies in the world.
- yes, cortex was born at weaveworks in 2016. tom wilkie (vp of product at grafana labs) co-created it while he worked there. after tom joined grafana labs in 2018, we decided to pour a lot more resources into the project, and managed to convince weave.works to move it to the cncf. this was a great move for the project and the community, and cortex has come a long long way in the last 2 years.
once again, a big hat tip to everyone who made this release possible. a big day for the project, and for prometheus users in general!
[edit: typos]