Hey guys! I have some elderly family members (and some not elderly) who cannot attend the wedding, but they would love to be there on the computer

I would also like to be able to talk with them as well. Is there something like Skype that is free and requires NO program/app downloading? Installing something will likely be too confusing for them. Need something with a link I can send out that they can just click and join. There will likely be about 10 total people from allover who may want to join. I'd like to be able to see them as well, so video a must. Thanks!!
Re: Need to Stream Wedding - Easy for Elderly
I looked and it was through GoToMeeting (GoToWebinar). Looks like you can do a 7 day free trial. Maybe test everything out on a 7 day trial and then use your FI's email to do another free trial in the week of your weddings, and you'll already know how everything works?
As far as interacting with them, if you want them to be able to speak back, they'll need a microphone on their device, and you won't be able to see them. It's not a 10-way video chat. Google Hangouts might be better for that purpose.