1. HTML5 semantic elements

    HTML5 offers some new elements, primarily for semantic purposes. The elements include: `section`, `article`, `aside`, `header`, `footer`, `nav`, `figure`, `figcaption`, `time`, `mark` & `main`.

  2. IntersectionObserver

    API that can be used to understand the visibility and position of DOM elements relative to a containing element or to the top-level viewport. The position is delivered asynchronously and is useful for understanding the visibility of elements and implementing pre-loading and deferred loading of DOM content.

  3. IntersectionObserver V2

    Iteration on the original API that also reports if the element is covered by another element or has filters applied to it. Useful for blocking clickjacking attempts or tracking ad exposure.

  4. cdatasection api

  5. document api: createcdatasection

  6. htmltablerowelement api: sectionrowindex

  7. htmltablesectionelement api

  8. htmltablesectionelement api: align

  9. htmltablesectionelement api: ch

  10. htmltablesectionelement api: choff

  11. htmltablesectionelement api: deleterow

  12. htmltablesectionelement api: insertrow

  13. htmltablesectionelement api: rows

  14. htmltablesectionelement api: valign

  15. intersectionobserver api

  16. intersectionobserverentry api

  17. intersectionobserverentry api: boundingclientrect

  18. intersectionobserverentry api: `intersectionobserverentry()` constructor

  19. intersectionobserverentry api: intersectionratio

  20. intersectionobserverentry api: intersectionrect

  21. intersectionobserverentry api: isintersecting

  22. intersectionobserverentry api: rootbounds

  23. intersectionobserverentry api: target

  24. intersectionobserverentry api: time

  25. intersectionobserver api: disconnect

  26. intersectionobserver api: `intersectionobserver()` constructor

  27. intersectionobserver api: `intersectionobserver()` constructor: `options.root` parameter can be a `document`

  28. intersectionobserver api: observe

  29. intersectionobserver api: root

  30. intersectionobserver api: rootmargin

  31. intersectionobserver api: takerecords

  32. intersectionobserver api: thresholds

  33. intersectionobserver api: unobserve

  34. performanceelementtiming api: intersectionrect

  35. svgsvgelement api: checkintersection

  36. svgsvgelement api: getintersectionlist

  37. html element: section

  38. javascript built-in: webassembly: module: customsections