Bitcoin Optech newsletter #409 is here:
- describes a draft BIP to replace the testnet4 test network with a successor
- Optech Newsletter #409 Podcast
https://bitcoinops.org/en/newsletters/2026/06/12/
Pol Espinasa posted to the Bitcoin-Dev mailing list a draft BIP, co-authored with Fabian Jahr, to replace testnet4 with testnet5...
https://bitcoinops.org/en/newsletters/2026/06/12/#draft-bip-for-testnet5
Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.
Testnet5?! At this rate, we're going to have to have total blowout party when we get to Testnet10.