+Requirements
+------------
+
+public-inbox requires a number of other packages to access its full
+functionality. The core tools are, of course:
+
+* Git (1.8.0+, 2.6+ for writing v2 inboxes)
+* Perl 5.10.1+
+* DBD::SQLite (needed for IMAP, NNTP, message threading, and v2 inboxes)
+
+To accept incoming mail into a public inbox, you'll likely want:
+
+* MTA - postfix is recommended (for public-inbox-mda)
+* SpamAssassin (spamc/spamd) (for public-inbox-watch/public-inbox-mda)
+
+Beyond that, there is one non-standard Perl package required:
+
+* URI deb: liburi-perl
+ pkg: p5-URI
+ rpm: perl-URI
+ (for HTML/Atom generation)
+
+Plack and Date::Parse are optional as of public-inbox v1.3.0,
+but required for older releases:
+
+* Plack deb: libplack-perl
+ pkg: p5-Plack
+ rpm: perl-Plack, perl-Plack-Test,
+ (for HTML/Atom generation)
+
+- Date::Parse deb: libtimedate-perl
+ pkg: p5-TimeDate
+ rpm: perl-TimeDate
+ (for broken, mostly historical emails)
+
+Where "deb" indicates package names for Debian-derived distributions,
+"pkg" is for the FreeBSD package (maybe other common BSDs, too), and
+"rpm" is for RPM-based distributions (only known to work on Fedora).
+
+Numerous optional modules are likely to be useful as well:
+
+- DBD::SQLite deb: libdbd-sqlite3-perl
+ pkg: p5-DBD-SQLite
+ rpm: perl-DBD-SQLite
+ (for v2, IMAP, NNTP, or gzipped mboxes)
+
+- Search::Xapian or Xapian(.pm) deb: libsearch-xapian-perl
+ pkg: p5-Search-Xapian OR p5-Xapian
+ rpm: perl-Search-Xapian
+ (HTTP and IMAP search)
+
+- Inline::C deb: libinline-c-perl
+ pkg: pkg-Inline-C
+ rpm: perl-Inline (or perl-Inline-C)
+ (speeds up process spawning on Linux,
+ see public-inbox-daemon(8))
+
+- Email::Address::XS deb: libemail-address-xs-perl
+ pkg: pkg-Email-Address-XS
+ (correct parsing of tricky email
+ addresses, phrases and comments,
+ required for IMAP)
+
+- Parse::RecDescent deb: libparse-recdescent-perl
+ pkg: p5-Parse-RecDescent
+ rpm: perl-ParseRecDescent
+ (optional, for public-inbox-imapd(1))
+
+- Mail::IMAPClient deb: libmail-imapclient-perl
+ pkg: p5-Mail-IMAPClient
+ rpm: perl-Mail-IMAPClient
+ (optional for lei and public-inbox-watch)
+
+- BSD::Resource deb: libbsd-resource-perl
+ pkg: p5-BSD-Resource
+ rpm: perl-BSD-Resource
+ (optional, for PSGI limiters
+ see public-inbox-config(5))
+
+- Plack::Middleware::ReverseProxy deb: libplack-middleware-reverseproxy-perl
+ pkg: p5-Plack-Middleware-ReverseProxy
+ rpm: perl-Plack-Middleware-ReverseProxy
+ (ensures redirects are correct when running
+ behind nginx or Varnish)
+
+* highlight deb: libhighlight-perl
+ (for syntax highlighting with coderepo)
+
+* xapian-compact (tool) deb: xapian-tools
+ pkg: xapian-core
+ rpm: xapian-core
+ (optional, for public-inbox-compact(1))
+
+* curl (tool) deb, pkg, rpm: curl
+ (for HTTP(S) externals with curl)
+
+- Linux::Inotify2 deb: liblinux-inotify2-perl
+ rpm: perl-Linux-Inotify2
+ (for lei, public-inbox-watch and -imapd
+ on Linux)
+
+- IO::KQueue pkg: p5-IO-KQueue
+ (for lei, public-inbox-watch and -imapd
+ on *BSDs)
+
+- Net::Server deb: libnet-server-perl
+ pkg: pkg-Net-Server
+ rpm: perl-Net-Server
+ (for HTTP/IMAP/NNTP background daemons,
+ not needed as systemd services or
+ foreground servers)
+
+The following module is typically pulled in by dependencies listed
+above, so there is no need to explicitly install them:
+
+- DBI deb: libdbi-perl
+ pkg: p5-DBI
+ rpm: perl-DBI
+ (pulled in by DBD::SQLite)
+
+Uncommonly needed modules (see HACKING for development-only modules):
+
+- Socket6 deb: libsocket6-perl
+ pkg: p5-Socket6
+ rpm: perl-Socket6
+ (pulled in by SpamAssassin and Net::Server,
+ only necessary if using IPv6 with
+ Plack::Middleware::AccessLog or similar
+ on Perl <= 5.12)
+
+- Crypt::CBC deb: libcrypt-cbc-perl
+ pkg: p5-Crypt-CBC
+ (for PublicInbox::Unsubscribe (rarely used))