Vitalik uses Firefly, Mask's social aggregation app, and said apps should support alternative clients.

TechFlow news, according to Foresight News, Vitalik Buterin used Firefly, a social aggregation application under Mask, to post yesterday: "This is a post published via Firefly, which can simultaneously publish to Farcaster and Lens. Alternative clients are important—we should support them!"

Foresight News editorial team has verified through on-chain data that the @vitalik account on Firefly belongs to Vitalik himself.