Apple's WebKit team is inviting developers to submit proposals for Interop 2027, a cross-browser initiative improving web technology consistency. Since its 2022 launch, Interop has grown from a one-off effort into an annual collaboration between Apple, Google, Microsoft, Mozilla, Bocoup, and Igalia to tackle interoperability challenges. The 2025 edition achieved remarkable progress, with test pass rates soaring from 29% to 97%, while 2026 will focus on 15 key areas including CSS features, Navigation API, View Transitions, WebRTC, and Web Transport.

Proposals for Interop 2027 must be based on mature, testable web standards and submitted through GitHub by September 23. Successful submissions require specificity, impact, value, stability, and test coverage, with developers encouraged to strengthen existing proposals rather than duplicating ideas. The initiative relies on automated Web Platform Tests to measure cross-browser progress, with Apple emphasizing that technologies needing more testing should be proposed as Interop Investigations instead.