For those who liked Grove and its combination of IRC and web chat, I personally recommend Flowdock which also has an IRC interface https://flowdock.com/ I know the people behind Flowdock personally and know that they are going to be around for a long time. As a personal note, it's sad to see Grove go away. It was the first bigger service I got to design and I loved working with Leah.
edit: dunno how I overlooked this before: https://www.flowdock.com/help/irc
thanks for making me look again, though!