Modern meaning dominates: the ByteDance collaboration suite (chat + docs + video + calendar). The classical meaning, 'fast-flying dispatch,' is preserved in dictionaries but rarely used outside historical fiction.
ByteDance's enterprise workspace app, launched 2019. Competes with 钉钉 (DingTalk) and 企业微信 (WeCom). International version branded 'Lark.' The name plays on the classical sense of 'fast-flying letter.'