Calitabby hosts a Matrix homeserver at matrix.calitabby.com. It is open for public registration and does not currently require an email address (this will likely change in the future however).
To join Calitabby Matrix, download a Matrix client such as SchildiChat or Cinny, and create an account using the matrix.calitabby.com homeserver.
The #crispycat:matrix.calitabby.com room serves as the crispycat community chat room and primary method of support, while the #lounge:matrix.calitabby.com is intended for more general discussion. Announcements regarding the Calitabby Network and crispycat projects are published in #announcements:matrix.calitabby.com.