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+Frequently Asked Questions
+--------------------------
+
+Why use man-db instead of man?
+==============================
+
+The man (currently http://primates.ximian.com/~flucifredi/man/) and man-db
+packages forked from a common code base in the mid-1990s. The original goal
+of man-db was, as indicated by the name, to add database caching to manual
+page searches. The increase in computer performance has considerably
+outpaced the growth of manual page collections, so some people now ask what
+the point is of using man-db rather than man.
+
+These days, the database is indeed not such an important difference between
+man-db and man, but there are several other areas where man-db does a
+significantly better job than man:
+
+ * Internationalisation
+
+ man uses the obsolete catgets system for translations of the messages
+ emitted by its programs, which cannot deal with the user using a
+ different output encoding (e.g. UTF-8) from that provided by the
+ translators. man-db uses gettext, which is more correct and robust.
+
+ In order to support many cases of non-English manual pages, man requires
+ manual hardcoding of iconv pipelines (or similar) and *roff device names
+ in its configuration file, and cannot operate correctly in environments
+ involving a variety of encodings. man-db handles all this out of the
+ box.
+
+ * Security and code quality
+
+ Security matters because both man and man-db can be installed setuid to
+ a special user, and also because man is sometimes used in semi-trusted
+ or untrusted contexts, such as from CGI scripts.
+
+ Both man and man-db spend a lot of time calling external programs, often
+ in pipelines. man does so by assembling strings which it then feeds to
+ the shell; this approach is nowadays well-known to be fragile and prone
+ to security vulnerabilities. man-db has been redesigned from top to
+ bottom to have safe and correct command execution, using a special
+ "libpipeline" library.
+
+ * Performance
+
+ Happily, dealing with manual pages is not normally a
+ performance-critical task these days; manual pages can normally be found
+ and rendered comfortably within expected interactive response times.
+ However, there are a few cases that are still more difficult, such as
+ 'man -K' to perform a full-text search on all manual pages. Neither man
+ nor man-db includes a proper full-text search engine, but there is
+ nevertheless a significant performance difference here: man-db performs
+ this search at least three times as quickly as man, and in some cases
+ much better than that. (On the test system, man took five minutes to
+ search all manual pages, severely degrading interactive performance of
+ the rest of the system for that time; man-db took around 40 seconds.)
+
+ * Maintenance
+
+ At the time of writing (February 2012), man-db has had ten full releases
+ since the start of 2008 with substantial feature work, while man has had
+ one release with a few minor changes.
+
+I have great respect for the people who maintain man, but as a project it
+has fallen badly behind. Rather than continuing to struggle along with
+complicated patch sets, those distributions that still use man would
+probably be better off switching to man-db.