Q: Could I chat with a Google Hangouts user via iChat on Mac?

Hi,

In theory yes. (if they are using a Mac)

GoogleTalk and hangouts appear to be XMPP/Jabber servers.

AS long as the other person (Buddy) is also on a Mac  and is using iChat or Messages with a similar Jabber account then your should be able to Video And Audio Chat.

It does seem that in line with Yosemite's dropping of the AIM and Jabber Screen Sharing that the SNATMAP server that connects iChat and Messages AIM  and Jabber A/V chats no longer supports Screen Sharing connections - which has an effect on earlier versions.

There was concern during Mavericks and Yosemite that Video and Audio Chats between AIM and Jabber Buddies was going to be stopped in favour of FaceTime only.

However they started working again in El Capitan and this seemed to be more to do with the SNATMAP server being sorted out rather than the progress map of the apps future.

In practice it can be a bit more fraught.

GoogleTalk IDs (@googlemail.com and @gmail.com) seem to do better than other Hangout names based on other domains such as IDs linked to work.

What cannot be done is iChat or Messages to a Web Browser login of to any PC app (there used to be a separate PC app called Google Talk) that can connect to the server.

9:09 pm      Tuesday; July 5, 2016

Hi,

When Google Talk  first came out the connections could be made with a Browser and the Flash Plug-in.

This could connect to the PC app of the same name but not other apps including iChat.

Later Google "invented" their own Browser Plug-in do do the same job.

It would still work in Safari and other browsers  but did not add Browser to iChat abilities.

I can see part of this page (I Don't use Facebook) https://www.facebook.com/video.calling.instructions/info?tab=page_info but it does not seem very helpful as to whether a Plug-in is needed or not.

This one https://3acd-downloads.phpnuke.org/en/c386157/facebook-video-calling suggests it is an Plug-in that uses Skype.

That suggests that it is not using Flash and that the FaceBook Messenger has moved away from XXMP (Jabber) to be able to use a Jabber specific App with the Jingle Video Module added on.

I am sorry that I can't help any further.

7:30 pm      Wednesday; July 6, 2016

Hi,

iChat (1) comes out with Text only chatting with an AIM valid ID and Apple start their Deal with AIM that Apple ID (@mac.com at the time) are recognised as AIM Screen Names).

The App also comes with an Automatic Bonjour Account *under the name Rendezvous at the time)

iChat 2 (So called iChat AV) is when Video starts. It is really Audio Only and Video.

At that time AIM is on about version 5.0 for PC versions and the video is compatible. (not to the Mac version though)

iChat 3 adds Jabber account (you manually have to change the server name if using a Google ID).

AIM is still compatible though AIM 5.5 on the PC side but not the Mac version.

Jabber A/V is Mac to Mac only. It does not do other Jabber apps that can do A/V (Those apps use Jingle and are not compatibile)

iChat 4 adds the Google option to add an Account.

Issues with AIM for PC compatibility start to arise. AIM 7 and 8 are really useless for most people.

iChat 6 (in lion) adds the Yahoo option but the Plug-in is not built like the AIM and Jabber ones and is Text Only (Does not include even File Sending). It has never done A/V chats or Screen Sharing.  Effectively A/V chat have become Mac to Mac only

Messages 7 (The numbering continues from iChat) In Mountain Lion has the iMessages foisted upon it.

You are forced in to Tabbed chats in the main window which also contains many of the interface items. (it is possible to get the Buddy Lists to show and also to separate them - they can even have their own Status Messages.).

The iMessages account does not invoke FaceTime at this time.

Many of the iChat features such as iChat Theatre and the Format Menu are still present.

Messages 8 in Mavericks has the ability to start up FaceTime for Video.

This is done from the Details item top right of the main window and has to start after a text chat has been started.  iChat Theatre disappears.

Around this time although AIM still support @mac.com and @me.com names the fact that the last version of iChat 6 (version 6.3 I think) onwards do a login to Apple and AIM to prove it is you logging in these IDs no longer work via iChat 1 though 6 (iChat 6.0)  Those older version also do not @icloud.com as a Name option but they also don't work in those versions.

Messages 8 in Yosemite  (Apple dropped the ball on numbering throughout Mavericks and Yosemite there are no sub number sets but you still need to use the right updated app with the right updated OS version).  This is different again from the Mavericks version despite the numbering issue.

Jabber and AIM have effectively become Mac to Mac only.

The AIM accounts can still use @mac.com @me.com registered and linked to iCloud and @icloud.com IDs as Valid AIM Screen Names.

There seems to be an issue with the SNATMAP server (how all AIM, Jabber and Screen Sharing connections are made).

The iMessages Account can now also invoke the Screen Sharing app using the iMessages ID to do Screen Sharing that way. It seems we are being pushed into this.

The Format Menu for text chats disappears as does the number of font options in the Preferences.

Messages 9 in EL Capitan. At the OS X 10..11.3 update the SNATMAP Server suddenly seems to come back to life and Messages using AIM and Jabber (including Google IDs) can Video and Audio Only chat again.  However AIM and Jabber Screen Sharing continues to not work and has disappeared from the Menu.

OS X 10.12/Messages 10 ? Who knows.  They have already ruined a perfectly good app but making it too iOS like and losing well liked features.

I hope this helps to explain things.

8:33 pm      Thursday; July 7, 2016