schemix
Schemix is an implementation of (a subset of) Scheme that runs inside the Linux Kernel OS, so you can dynamically debug your device-drivers.It has not been actively maintained since 2003, and hasn't been ported to the 2.6 kernel.
Schemix is a Scheme system, implemented as a patch to the Linux kernel. It aims to attain R5RS compliance while remaining small, fast and easy to understand.The intended use of Schemix is for exploration of the Linux kernel and for rapid, interactive prototyping of Linux drivers and other new kernel features. To achieve this, Schemix attempts to make a large subset of the kernel functionality available to Scheme programs. Interactivity is via a character device, /dev/schemix which presents a REPL (Read, Eval, Print Loop) to anyone having access to the device.