Intel NUC boards - Four-by-four inch Intel NUC boards come with a soldered-on processor.
esp32 - A very cheap small chip, compatible with Arduino.
ESPRESSObin - Electronics, Single Board Computer, and x86
Intel NUC - Intel NUCs are available as Kits(Barebones), Boards(Mainbaord only) and as perconfigured Mini-PCs.
Helios4 - The Open Source and Open Hardware Network Attached Storage (NAS). Build your own PrivateCloud: Store music and movies, share photo albums with friends, protect your files and never fear losing data again.
Qualcomm DragonBoard - https://developer.qualcomm.com/hardware/dragonboard-410c