The Kovan testnet has a long and interesting history. Born out of the necessity to get away from a trivially attackable Ethereum PoW testnet, Kovan was one of the first public PoA networks.
While serving as a testbed for many application developers to quickly iterate and experiment, over time it also became a testbed for new Parity technologies like Wasm smart contracts, Aura-specific features and other things that are easier to test when you have a single-client network.
It was always our hope that eventually we would get more and more validators and community members to take an interest and start participating in the network. Over the last year however, we have unfortunately lost more validators than we have gained. We have found that more and more people spin up their own application-specific testnets to test things like Wasm.
We’re entering a new era of cross-client PoA testnets. With efforts to spawn more temporary hard-fork testnets to replicate mainnet as well as efforts like the Görli Testnet to create a proper cross-client PoA testnet, we live in a different world than when Kovan started.
Parity has reached out to multiple former validators and new parties that may be interested in running a validator node and taking stewardship of the testnet and we hope that someone will step up and take the network forward in an interesting way. While there are currently other participants supporting the testnet, Parity itself will stop running its validator node on April 26th, 2019. If you would like to become a validator on Kovan, please reach out on the Kovan chat on Riot.
We thank everyone who played a part in the history of this network, and hope that it finds a good future with new leadership.
Update 15-5-19: Kovan has successfully switched over to a community-maintained validator set. Update to 2.5.1 or 2.4.6 to get the new chainspec for Kovan.