Kovan Testnet proposalHappened on March 1st, 2017This proposal is to introduce a new testnet to provide a stable, secure testnet environment for Ethereum developers, due to the instability of the existing Ropsten testnet.
On 24th Feb 2017, Ropsten was under a denial-of-service attack (“spam attack”). Average block propagation time has since slowed to a crawl as a large miner has decided to deploy several zero-value high-gas transactions to spam the test network continually.
The attacker’s intentions are unknown, but the result is that Ethereum developers who rely on Ropsten no longer have a stable public testing environment to deploy and test their smart contract code prior to deploying to production on the mainnet chain.