Technology entrepreneur and Tesla CEO Elon Musk has sparked a conversation with ether (ETH) co-founder Vitalik Buterin with his laconic one-word tweet “Ethereum” on April 29.

The tweet, which Musk swiftly ironized by adding “jk” within the same thread, prompted Buterin to extend an invitation to Musk for Ethereum’s DevCon in October. In response, Musk asked Buterin the question, “What should be developed on Ethereum?”

Buterin listed five of his top picks for the network’s developments, peppered with references to his own past Twitter threads and Ethereum research content.

Foremost among these is the creation of a “globally accessible financial system, including payments, store of value [...] insurance,” as well as a disintermediated ETH-powered digital identity infrastructure.

Buterin also proposed the creation of registries and certificates that would be digitally signed, certified and even revoked on-chain — which Buterin had previously pitched as part of a self-described tweetstorm on non-financial applications for blockchain in December 2018.

He further referred to the use of the ETH blockchain for “experimenting with new forms of human organizational structure,” and to enable micropayment use cases via ETH payment channels.

Other proposals from Buterin included crypto-powered “markets for personal data for privacy preserving machine learning,” and using “cryptoeconomics for spam prevention in social networks.”

Buterin lastly noted that blockchain can be a testing ground for “new market designs, eg. frequent batch auctions, combinatorial auctions, automated market makers,” and that the technology can power both identity, reputation and credit systems for disenfranchised social groups, and even to construct decentralized DNS alternatives.

In contrast with Buterin’s lengthy engagement with Musk’s lead-in, other blockchain creators — such as Tron Foundation CEO Justin Sun — responded in kind, with their own one-word quips.

Musk only briefly re-engaged in the conversation with an allusion to Buterin’s official Twitter handle, “Vitalik Non-giver of Ether,” cajoling Vitalik to “Stop giving away free ETH!”

EToro analyst Mati Greenspan meanwhile speculated that Musk’s single tweeted word had allegedly prompted a mini spike in Ethereum’s price.

As previously reported, Musk has praised bitcoin’s (BTC) structure as being “quite brilliant,” yet underscored the problematic energy intensivity of mining the coin. The Tesla founder has claimed he owns only a fractional amount of BTC, allegedly sent to him by a friend years ago.