tl;dr: DuckDB 2.0.0 LTS ("Cinnamon Teal") ships with ~20,000 commits since 1.5, adding the Quack client-server protocol, async I/O for faster reads from object storage, a first-class VARIANT type with shredding, SQL triggers, and a new PEG-based extensible parser that replaces the PostgreSQL-derived one. Other additions include an agent mode in the CLI for coding assistants, a revamped C API v2 with self-hosted extension repositories, and dialect features like NEAREST joins and nested schemas. Breaking changes include a new storage format unreadable by older versions, C++17 requirement, and deprecation of single-arrow lambda syntax.