Byzantium, the first part of ethereum’s long-awaited Metropolis upgrade, has officially launched on testnet.

The simulated hard fork was executed this morning on Ropsten, the ethereum testing environment, and is expected to run for a few weeks of troubleshooting before the fork occurs on the main ethereum blockchain, currently the world’s second-largest by market capitalization.

The testing period will involve a trial of the nine EIPs (ethereum improvement protocols) to be introduced in the Byzantium hardfork. As previously detailed by CoinDesk, the code updates will introduce changes to increase the functionality of the network while minimizing potential exploits and also paving the way for novel cryptography on the ethereum platform.

Looking ahead, testing will likely take about three weeks, suggesting the actual Byzantium hard fork is likely to occur sometime around October 9. However, this is contingent on whether the test does not cause unanticipated problems.

Speaking at the ethereum core dev meet up on September 8, ethereum founder Vitalik Buterin said he expected the testing period will require around three to four weeks. In response, developer Péter Szilágyi stated that the tests may need less time, because “if things go wrong….they will go wrong fast.”

The ethereum developers are expected to announce a formal date for the hard fork shortly – provided everything runs according to plan.

You can watch a live infographic of the Byzantium fork on Ropsten here.

Blue cells via Shutterstock