We use the following clients for Mozilla meetings:
IRC (Internet Relay Chat) is an instant messenger. Most meetings are held on the #sumo channel and you can connect with mibbit via this link if the meetings are on IRC. For other ways to connect please visit https://wiki.mozilla.org/IRC.
Vidyo is Mozilla's own meeting system.
If you are a Mozilla employee you can login via https://v.mozilla.com.
If you are a contributor, you will need a guest link. It will be provided on the etherpad and will look something like this "https://v.mozilla.com/flex.html?roomdirect.html........". Please note that you need to download and install Vidyo Client before you can use the guest link. When you go to the guest URL login page it will look like this:
This is held every Wednesday at 9:00 a.m. PT.
To know more about SUMO meetings, visit the SUMO Meeting page on Mozilla wiki.