Have been using llama.cpp, whisper.cpp, Stable Diffusion for a long while (most often the first one). My “hub” is a collection of bash scripts and a ssh server running.

I typically use LLMs for translation, interactive technical troubleshooting, advice on obscure topics, sometimes coding, sometimes mathematics (though local models are mostly terrible for this), sometimes just talking. Also music generation with ChatMusician.

I use the hardware I already have - a 16GB AMD card (using ROCm) and some DDR5 RAM. ROCm might be tricky to set up for various libraries and inference engines, but then it just works. I don’t rent hardware - don’t want any data to leave my machine.

My use isn’t intensive enough to warrant measuring energy costs.

Disabling root login and password auth, using a non-standard port and updating regularly works for me for this exact use case.

Primarily as a personal knowledge database, but also management of what, how and when is to be done (not for reminders or external motivation; rather to form a mental picture and understand the priorities). In future, I’ll also use it to track the state of various ongoing affairs as the need arises, and perhaps integrate local programs and APIs into the wiki pages (that’s probably where I’d need to write custom MW extensions).

I have a MediaWiki instance on my laptop (I’ve found the features of all other wikis/mindmaps/knowledge databases decisively insufficient after having a taste of MW templates, Semantic MediaWiki and Scribunto).

Also some smaller things like pihole-standalone, Jellyfin and dictd.