Wikipedia
Smallfoot is the name of both a Rapid application development toolkit and an embedded operating system designed and released by Caldera Systems/ Caldera International/ The SCO Group in both UnixWare and Linux formats. Created for use in embedded environments such as point of sale systems and gaming, the toolkits are used to create specifically tailored operating systems geared towards the desired use. These customized and stripped down versions of the operating systems make less of a footprint, hence the names Smallfoot embedded UNIX and Smallfoot embedded Linux respectively.
Smallfoot is also notable in that it was a key Linux product of The SCO Group, developed for both the UNIX and Linux platforms and distributed by SCO and Caldera Systems/ Caldera International after its purchase of SCO. In the SCO vs IBM lawsuit, SCO denied distribution of Linux kernel code, however SCO Smallfoot is based on both 2.4.10 and 2.6.1 Linux kernel versions.