Offline Knowledge
https://internet-in-a-box.org/
Internet-In-A-Box (IIAB) prefers the Raspberry Pi for its server hardware, though NUCs are acceptable
The Raspberry Pi 4 ($35+), Raspberry Pi 5 ($45+) and Raspberry Pi 500 ($100 computer-in-keyboard) are best for classrooms, in almost all cases! Their internal Wi-Fi hotspot supports up to 32 student WiFi client devices (but see #823 for the very latest Wi-Fi firmware info!) RECOMMENDATION: Buy any Raspberry Pi with at least 2 GB RAM, especially if your Internet-in-a-Box will include Kolibri, Moodle or Nextcloud. The older Raspberry Pi 3 and 3 B+ ($35+) are also possible, despite their 1GB RAM limitation.
Finally the Raspberry Pi Zero W ($10) and Raspberry Pi Zero 2 W ($15) work great as learning kiosks, despite their meager 512MB RAM (Internet-in-a-Box is used in rural medical clinics, and by families in their homes).
NOTE that your microSD card should be prepared with IIAB software and provisioned with Content in a more powerful Raspberry Pi — then later insert the microSD into your Zero (2) W. (It continues to astonish us how powerful these tiny computers really are, the size of a cigarette lighter yet able to serve 32 students simultaneously, with their powerful built-in Wi-Fi!)
Mini PC's like the ASUS NUC (acquired from Intel in 2023): Avoid classic/desktop PCs whenever possible, as they consume far too much electricity. However: tough, well-rounded, low-power Mini PCs (such as the NUC) world extremely well, and have proven very effective as school servers in the developing world since 2014. We prefer Mini PC's models that accept 2.5-inch SATA drives (HDD or SSD) and work with DC voltages up to 19V. WARNINGS:
The internal Wi-Fi in most NUC computers is regrettably blocked from connecting to more than 12 Wi-Fi client devices. Compare this to the Raspberry Pi's mentioned above — whose internal Wi-Fi can support 32 simultaneous Wi-Fi client devices!
Low-end NUC models only work right near 12V, and so are not reliable using lead-acid batteries that you find in most solar installations. Read the spec carefully, for the exact model you're considering!
Finally: the NUC is not a fan-less device, but nevertheless has proved very reliable across diverse climates.
Other Mini PC competitors: MSI units have proven very solid, and Zotac perhaps less so. Consider also Beelink's NUC clones, and Gigabyte BRIX (e.g. GB-BSI3H-6100) which likewise is almost an exact clone of the NUC. The BRIX allows internal Wi-Fi to scale beyond the NUC's annoying limitation of 12 connections maximum, if you insert an appropriate Atheros Wi-Fi module (typically < $10) into the BRIX. George Hunt can answer questions around which Atheros Wi-Fi modules have been tested to work, as of February 2017. Recap: scaling up internal Wi-Fi is sadly not possible with NUCs since 2015 (5th generation NUCs and onwards) as the NUC's Wi-Fi module is unfortunately soldered in.
Project NOMAD does the same thing but staples a LLM onto the whole mess and makes it easy to upload your own custom information (i.e., pdf & word documents). It can be installed on a laptop or a low-end desktop, but the recommendation is to either put it on a NUC (ASUS, Beelink) or a real server with a graphics processor.