Programming has not changed much since the 1960's and 1970's when Unix and C were developed. Modern computer programming languages simply mix and match different features from the "Cambrian explosion" of experimental and production programming languages in the 1960's. Hence it is not surprising that books on general programming concepts and principles are still relevant years later.<p>C is still in widespread use in operating system internals, embedded software development (think wearables and Internet of Things), complex algorithms like video compression, and miscellaneous other fields.<p>Version control dates back at least to SCCS in the 1970's and has been in widespread use at least since RCS in the 1980's. I mention this because I occasionally encounter people who seem to think version control either was invented with Git (not true) or rarely used before Git (not true).<p>Testing software is not new. Testing fanaticism is new.<p>Things that have improved in programming are:<p>Optimizing compilers have improved and all but eliminated low level loop optimizations by hand and similar "micro" optimizations by hand. This has also largely eliminated assembly programming.<p>Computers are much faster than in the 1960's, not much faster than the late 1990's, which means many things can be done with scripting languages that were once too slow. Compiled languages like C and C++ still dominate at the very high end of performance.<p>Scripting languages play fast and loose with variable types which makes it easier to write code quickly, but makes it harder to achieve the speed of a compiled executable from a relatively strongly typed language (compared to a scripting language -- how strongly typed is C really with its casts, pointers, and other unsafe but useful features?).<p>Compiler error and warning messages are much clearer than years ago.<p>There have been some incremental improvements in programming languages like using the plus sign (+) to concatenate strings that have made many new languages a bit easier to read and write. Compare strcat(blatz, " and now") to blatz + " and now"<p>None of these, or other improvements in the last fifty years, are revolutionary advances that would obsolete an older book on general programming principles.<p>Computer programming remains labor intensive and often highly compensated because many of the problems and issues remain largely unchanged since the early days (1960's/1970's).