This second edition covers a large range of cluster topics. Firstly, in terms of why you might need a Beowulf. Then, how to assemble the hardware. And how to install linux on the nodes. The book is valuable not least because it encapsulates decades of knowledge about running clusters, not just of the Beowulf type. The chapters' authors hail from places like Argonne and Oak Ridge National Labs, where there have been research groups using many different types of clusters for years.

Aside from linux, the book describes the special purpose parallel language called MPI. It can be accessed from a C, C++ or Fortran program. Note this choice of languages. Typically the cluster is meant for intensive computational use, with UI issues a low priority. So the book focuses on those languages, and not how to hook Java or C# to MPI.

Of course, with each chapter written by a different author, there is somewhat of a discontinuity between chapters. Think of the book as more akin to a conference proceedings writeup.