If they use Youtube or Skype, they use some of them. Any online/app audio/video chat thing will probably use a mixture. Depending on how your office VOIP phone

If they use Youtube or Skype, they use some of them. Any online/app audio/video chat thing will probably use a mixture. Depending on how your office VOIP phone works, or the PBX it's connected to, or your POTs carrier, you might be using those technologies. Maybe the CCTV at your work uses them too... If you are building a multimedia thing, and you don't want to worry about paying for patents, you might reach for one of these. Your users won't know.