1. document api: activeelement

2. document api: activeviewtransition

3. elementinternals api: ariaactivedescendantelement

4. element api: activeviewtransition

5. element api: ariaactivedescendantelement

6. mediasession api: `setcameraactive()`

7. mediasession api: `setmicrophoneactive()`

8. mediasource api: activesourcebuffers

9. mediastream api: active

10. mediastream api: `active` event

11. mediastream api: `inactive` event

12. navigator api: activevrdisplays

13. navigator api: activevrdisplays: secure context required

14. performancetiming api: dominteractive

15. rtcrtpsender api: `setparameters()`: `parameters.encodings` parameter: `parameters.encodings.active` parameter

16. rtcstatsreport api: `outbound-rtp` stats: `active` in 'outbound-rtp' stats

17. serviceworkerregistration api: active

18. shadowroot api: activeelement

19. subscriber api: active

20. texttrack api: activecues

21. useractivation api: hasbeenactive

22. useractivation api: isactive

23. webgl2renderingcontext api: activetexture

24. webgl2renderingcontext api: getactiveattrib

25. webgl2renderingcontext api: getactiveuniform

26. webglactiveinfo api

27. webglactiveinfo api: name

28. webglactiveinfo api: size

29. webglactiveinfo api: type

30. webglactiveinfo api: available in workers

31. webglrenderingcontext api: activetexture

32. webglrenderingcontext api: getactiveattrib

33. webglrenderingcontext api: getactiveuniform

34. xrsession api: depthactive

35. css property: timeline-trigger-active-range

36. css property: timeline-trigger-active-range-end

37. css property: timeline-trigger-active-range-end: auto

38. css property: timeline-trigger-active-range-end: normal

39. css property: timeline-trigger-active-range-start

40. css property: timeline-trigger-active-range-start: auto

41. css property: timeline-trigger-active-range-start: normal

42. css property: timeline-trigger-active-range: auto

43. css property: timeline-trigger-active-range: normal

44. css selector: `:-moz-window-inactive`

45. css selector: `:active`

46. css selector: `:active-view-transition`

47. css selector: `:active-view-transition-type()`

48. css selector: `:active`: non-`a` element support

49. internet explorer features