Most TDLI systems that are deployed make use of second hand and/or donated computer hardware. In practice this means small energy-efficient system boards designed for embedded applications and Thinkpad X, T and W series portable computers for mobile labs. We also make extensive use of the FreeBSD and DragonflyBSD operating systems for workstations, networking and file-storage applications. This results in highly reliable, scalable and predictable environments that can be tuned in various ways.