Two major testnets are conducted in June 2020. One is Altona, the most recent Ethereum 2.0 iteration to be launched on testnet this coming Monday, June 29. But before that, a single-client version called Onyx was launched on testnet last June 10.

Since its announcement, investors and enthusiasts alike have been waiting patiently for the implementation of Ethereum 2.0, the king of all Ethereum upgrades. And every day we are drawing closer to Phase 0, which would initiate the Proof-of-stake protocol that will run on the new Ethereum implementation.

But before they could do that, two testnets had to be released first.

Onyx Test Network

Onyx is “aimed to be the final, non-trivial spec update before mainnet for phase 0”, according to Prysmatic Labs, one of many dev teams working on Ethereum 2.0.

The Onyx testnet is one of five milestones laid out by Prysmatic Labs. The Diamond milestone, which comes after Onyx, will ultimately be the turning point of the Ethereum network. By then, the first version of Ethereum 2.0 will go live on mainnet for the first time and sharding will be introduced to the system.

Five Milestones of Prysmatic Labs: Ruby, Topaz, Sapphire, Onyx, and Diamond

But going back to the present, the Onyx testnet worked on version 0.12.1 of the Ethereum 2.0 specification, aimed to be the last one before it becomes multi-client ready. But Onyx is merely a single-client testnet that is comprised of only Prysm validators. If we want to mimic true Eth 2.0 mainnet conditions, we need a multi-client testnet.

Altona Test Network

The Altona testnet will feature four clients from the start, unlike Onyx.

Multi-client testnets are crucial because devs need to simulate mainnet conditions as closely as possible to ensure that they can cover as much ground and fix as many issues as possible before the real thing comes. And this requires stable, long-term testnets that are always up and running and are supported by multiple clients.

The main goal of Altona is to pave the way for the beacon chain — Ethereum’s proof of stake blockchain which is set to initially work alongside the proof of work chain as a dual consensus system.

With so many projects depending on Ethereum’s upgrade (especially DeFi), many investors are hoping for a more specific timeline.

But despite all the progress that has been made, there has been no specific announcement for the long-awaited mainnet release of Phase 0. Fortunately, Altona is likely to be the last step before we can finally move forward to Phase 0. The question is, how long is the testnet gonna last before they decide to go on mainnet?