MongoDB Basics
David Hows & Peter Membrey & Eelco Plugge
Mastering Chef
Mayank Joshi
Pro Linux High Availability Clustering
Sander van Vugt
Mostly Harmless
Douglas Adams
The Hitchhiker's Guide to the Galaxy (5)
Getting Started With Varnish Cache: Accelerate Your Web Applications
Thijs Feryn
Getting Started With Memcached
Ahmed Soliman