Eclair v0.9.0 is a significant release that lays the groundwork for advanced Lightning Network features such as dual-funding, splicing, and Bolt 12 offers. While these features are implemented, they are not yet fully activated pending finalization of specifications and cross-compatibility testing with other implementations. This release also enhances plugin capabilities, introduces measures against various DoS attacks, and improves overall performance. Users should exercise caution when activating new features due to potential backwards-incompatible changes. The release is fully compatible with previous versions, allowing seamless upgrades without closing channels. Detailed release notes and verification instructions are available on the GitHub page.