A round-up of ones I noticed relatively recently, some of current value, some historical:
- Open Access Bibliography by Charles Bailey (OAN).
- Scholarly Communication, the Information Chain and Technology: Analyses and Reflexions by Neil Jacobs
- Unified mathematical treatment of complex cascaded bipartite networks: The case of collections of journal papers by Steven A. Morris
- A Short Introduction to Operating Systems
- Understanding Algebra by James Brennan
- Programming Languages by Scott F. Smith
- Oracle Grid Computing Glossary
- Introduction to Matrix Algebra by Autar K. Kaw
- Getting the most out of vacuum tubes and over a dozen other historical technical books (MAKE).
- Dictionary of Algorithms and Data Structures (Topix).
Textbook Revolution is a good aggregator site (OAN).