This is a custom built mini PC, with a mini-ITX motherboard and an Intel N100 CPU. It gets powered by a power supply that I got from an old computer. Also, it needs no active cooling, just a heatsink. It almost never gets above 60°C.
Yes, this is it. I bought it because it was cheap (100€) and had a built-in CPU. The only problems are that it hasn't got many SATA or PCIe ports. This is fine however, because I have no need for them right now.