When the article was written, my workplace communicated over e-mail (IMAP-enabled), our calendars supported CalDAV, and we did have an instant messaging system that ran over extensions to SIP, which _was_ compatible with libpurple. We also all had voice phones on our desks for very-impromptu calls. The ironic part of all this: it was Microsoft Exchange and Microsoft Lync. I at the time was using Linux with Pidgin and Evolution, there being no Microsoft clients for any of the stack.
Nowadays, our stack is GApps with Slack, and a heathy dose of Zoom. To get Slack out of the way: good luck; the XMPP and IRC gateways were retired ages ago, and interactive API clients even today appear to be second-class citizens. GApps is interesting in that they do support standards like IMAP and CalDAV, but only if your organization allows for "insecure authentication" options, which mine does not. Otherwise, you're glued to a browser app that sometimes breaks in browsers that aren't Chrome. And let's not even start with Zoom.
My point in saying this is: in 2014, this would have been seen as a cool project, and I'd bet some coworkers would've even encouraged me to try and get it working. In 2021, this is how I'd get fired.