Questions that are independent of programming language.  These questions are typically more abstract than other categories.

Free Language Agnostic Programming Books

• 97 Things Every Programmer Should Know
• Algorithms and Data-Structures (PDF)
• Algorithms (course)
• The Architecture of Open Source Applications
• The Art of Unix Programming
• Best Kept Secrets of Peer Code Review
• Binary Trees (PDF)
• The Cathedral and the Bazaar
• Clever Algorithms
• Communicating Sequential Processes (PDF) - Tony Hoare
• Compiler Construction (PDF)
• Computer Musings (lectures by Donald Knuth)
• Data Structures and Algorithms: Annotated Reference with Examples
• Database Fundamentals (PDF)
• Data-Intensive Text Processing with MapReduce (PDF)
• The Definitive Guide to Building Code Quality
• Designing Interfaces by Jennifer Tidwell
• Digital Signal Processing For Engineers and Scientists
• Domain Driven Design Quickly
• Don't Just Roll the Dice (PDF)
• Essentials of Metaheuristics by Sean Luke
• Essential Skills for Agile Development
• A Field Guide To Genetic Programming
• Flow based Programming
• Foundations of Computer Science - Al Aho and Jeff Ullman
• Foundations of Programming
• Getting Real
• Getting started with Open source development (PDF)
• The Great Tree List Recursion Problem
• Guide to the Software Engineering Body of Knowledge
• How Computers Work
• How to Design Programs
• How to Think Like a Computer Scientist
• How to Write Parallel Programs
• How to write Unmaintainable Code
• I Am a Bug
• An Introduction to the Theory of Computation
• Introduction to Functional Programming (class lectures and slides)
• Introduction to Information Retrieval
• Is Parallel Programming Hard, And, If So, What Can You Do About It?
• Learn to Program
• Let's Build a Compiler
• Linkers and loaders
• Linked List Basics
• Linked List Problems
• Mathematical Logic - an Introduction (PDF)
• Matters Computational
• Mining of Massive Datasets
• NASA Manager Handbook for Software Development (PDF)
• NASA Software Measurement Handbook
• Object-Oriented Reengineering Patterns
• Online Course Materials
• Operating Systems and Middleware (PDF and LaTeX)
• Patterns and Practices: Application Architecture Guide 2.0
• Patterns of Software: Tales from the Software Community (PDF)
• Planning Algorithms
• PNG: The Definitive Guide
• Pointers And Memory
• Producing Open Source Software
• Programming Languages: Application and Interpretation
• Programming Methodology
• Programming Pearls
• Project Oberon (PDF)
• Seamless Object-Oriented Software Architecture(PDF)
• Security Engineering
• Structure and Interpretation of Computer Programs
• Summary of the GoF Design Patterns
• The Little Book of Semaphores
• The TCP/IP Guide
• Think Stats: Probability and Statistics for Programmers (PDF, code written in Python)
• Type Theory and Functional Programming
• Understanding IP Addressing: Everything you ever wanted to know (PDF)