You can also still connect to Google Talk with compatible third-party apps, like Pidgin and Gajim.
And a longer summary from the Wikipedia page on Google Talk:
Google Talk is an instant messaging service that provides both text and voice communication. […] As of March 2015, it is not discontinued – despite reports to the contrary – and officially remains available over XMPP in third party applications.
Google Talk was also the name of the client applications previously offered by Google to use the service. […] As of February 2015, the Windows client ceased to work, with email notifications sent to users who attempt to login, recommending that they try Google Hangouts instead.
In May 2013, Google announced that it would be dropping support for XMPP federation, and it did so one year later. However, XMPP federation is separate from general XMPP support. As of March 2015, Google Talk continues to support clients using the open XMPP protocol. Such clients are available for a number of operating systems not supported by the Google Talk client.
Google retaining XMPP support is great news for chat standards; it makes me think that they’re hopefully going to keep XMPP support for chat for at least longer than I originally expected (but then again, I had low expectations). I especially welcome this news because at home and work, I could have text messages right now in SMS (cell texting), IRC, Twitter mentions, Twitter messages, Facebook, Facebook Messenger, my personal Google Hangouts/Talk, my work Google Hangouts/Talk, Sqwiggle, my personal Skype, my work Skype, Slack, and probably a few others I’m forgetting. I’d really love more services to use standards (XMPP or otherwise) just so I could have one way of checking for messages (let alone respond to them). This is notable because more chat services are becoming walled gardens than ever before; interoperability is something we’ve lost. But maybe things are looking up.
(Speaking of Slack – which I haven’t used much beyond testing – I was very happy to find out that they offer both XMPP and IRC gateways. That’s amazing for a chat service launching in 2013… which is sad statement in many ways.)
Of course, email is a different story – it’s been standardized for a long time, for better or worse – so longer messages tend to go there, whether it’s from an email client, or a service that emails me, like LinkedIn. (I don’t really think it counts if you can’t respond via email, though. GitHub does that really well, but Facebook doesn’t.) Sure, email is the lowest common denominator, but that’s because everyone has an email address. To understand the state of chat in 2015, imagine if you could only email other Gmail users if you had a Gmail account, or Yahoo Mail users if you had a Yahoo account. If that sounds crazy, replace “mail” with “chat” and realize that’s what we’re doing.
Anyway, the above is just a long, drawn out way of saying: it’s not that I don’t like shiny new things like Kik, SnapChat, Viber, WhatsApp, or whatever comes next… it’s just that I have enough ways for people to send me a short message and they all seem pretty much the same, besides who I happen to need to talk to. Honestly, I’m more likely to close accounts than open new ones.