Last month, I noticed the Apache Server Bible, a fat, perhaps four inch, volume from SAMS. The age is suggested by the cover note that it "Covers Windows 95 and Windows NT Platforms!" The front matter gives a copyright year of 1999. The stable version of the Apache web server was then 1.2 something; it is now 2.4. There is a fair bit of information about using Perl for scripting, but nothing at all about PHP, which shortly became far more popular than Perl. Python is mentioned in passing, but there could be no mention of WSGI, which came out in 2003.
Could one use the book? I assume that some of the directives for some of the modules, for example, mod_proxy, remain the same. Would I use the book? Probably I would not. I am used to going to the on-line documentation for that. But I am not an expert on Apache or a steady user: almost all that I have done with it lately uses either mod_proxy or mod_wsgi.
After I looked over the Apache Server Bible, I had a look on my own shelves at work, and had no trouble finding several of comparable age. Few of them have been on the desk and open lately. Apart from that, their possible relevance varies.
Programming Perl has a 1996 copyright date. I have used it until the front cover fell off. I suspect that an awful lot of my use has been to check the rules on the module Getopt::Long. Twenty years ago, I might have put in some time reviewing the rules around references, but not lately. I think that within the last fifteen years Modern Perl and Effective Perl Programming have been the books I checked first.
Oracle Design, by Ensor and Stevenson, has a 1997 copyright date. I read it thoroughly, as shown by marginal jottings. A good deal of the advice remains sound. But the Oracle database has gone through about 10 versions since then (they wrote mostly about Oracle 7), and there have been many enhancements to Oracle's SQL and PL/SQL. And databases in general have jumped several orders of magnitude in size (number of records) since those days.
Refactoring, by Martin Fowler, copyright 1999, has held up pretty well, I think. It is written for an early version of Java, and object-oriented programming is less dominant, or anyway trendy, than it was in 1999. Still, it has advice to consider.
My copy of Computer Architecture: A Quantitative Approach by Hennessy and Patterson is quite old, copyright 1990. There have been a number of editions since then. It was written in the early days when RISC seemed to be undergoing a Cambrian Explosion, and RAID for storage was not yet invented. (Well, Patterson et al. hadn't yet popularized the notion.) But the principles remain sound. It is a student's book, and I should hand it off to a student who doesn't need the latest thinking.