Zabbix collect all the data (for exemple, cpu usage, memory usage, disk space etc…) Grafana take this data from zabbix and display it, You can create dashboards with only the useful data you need!
TubeArchivist is indeed “selfhosted youtube” but more importantly it’s more of a Youtube Backup, if you watch a lot of content on there, like me, you know that videos gets deleted all the time, and archiving videos that you like is really important (at least if some videos means a lot to you, like me)
And a XMPP server is just a self-hosted messaging/calls service that works like email and is decentralized. I’m not that familliar with it yet, but i’m loving the concept