0xchat full version is feature-rich: it supports NIP-17 DMs, NIP-29 group chats, MLS group chats, and more. 0xchat lite version is closer in concept to WhiteNoise: it focuses on MLS group chats, with privacy features like encrypted local database and encrypted media uploads. Both 0xchat lite and WhiteNoise use nip-ee, so in theory they’re interoperable — but currently there are some technical issues, so cross-app interoperability isn’t fully working yet.