At RAL we have some Beowulf clusters for running the Unified Model.
Our first cluster, based on Pentium 3s, was named after JRR Tolkien, whose works include a translation of, and commentary on, Beowulf.
More recently we have acquired two new clusters based on Pentium 4s. These have been named after CS Lewis and Charles Williams.
The common theme is the Inklings, a group of fantasy authors who met in an Oxford pub for literary and theological discussion in the 1930s and '40s.