The waffle.tech Matrix homeserver has been in service and open to the public since 2016. Registration is open, however, we do not host a web client like some Matrix servers do (there's little value in it since it'd be the same web client you'd find anywhere else). You can register by launching Element Web or another Matrix client, choosing to create an account, and changing the homeserver selection to “waffle.tech.”
Matrix homeservers can sometimes be a frustrating venture due to performance and stability challenges. Waffle.tech currently runs Synapse on a large machine and has maintained very reliable uptime (five-nines) for the last several years and, since the move to a newer and more generously equipped server, good performance. You may occasionally still see sluggishness, particularly during initial synchronization of large rooms. Fortunately, because it is a multi-user homeserver, many of the popular large rooms (e.g. related to large open-source projects) are already synced.
There are no approval requirements for new users. However, to deter abuse, email confirmation is required and recent registrations are manually reviewed. Your account will work immediately, but if you registered with a temporary email service, you can expect it to stop working soon.
Waffle.tech has historically hosted an XMPP server as well. However, usage was very low, so it was retired years ago. We continue to monitor the open messaging landscape and might offer other options in the future.