i3 has the following dependencies:

   "min" means minimum required version
   "lkgv" means last known good version

┌─────────────┬────────┬────────┬────────────────────────────────────────┐
│ dependency  │ min.   │ lkgv   │ URL                                    │
├─────────────┼────────┼────────┼────────────────────────────────────────┤
│ pkg-config  │ 0.25   │ 0.26   │ http://pkgconfig.freedesktop.org/      │
│ xcb-proto   │ 1.3    │ 1.6    │ http://xcb.freedesktop.org/dist/       │
│ libxcb      │ 1.1.93 │ 1.7    │ http://xcb.freedesktop.org/dist/       │
│ xcb-util    │ 0.3.3  │ 0.3.8  │ http://xcb.freedesktop.org/dist/       │
│ libev       │ 3.0    │ 4.04   │ http://libev.schmorp.de/               │
│ flex        │ 2.5.35 │ 2.5.35 │ http://flex.sourceforge.net/           │
│ bison       │ 2.4.1  │ 2.4.1  │ http://www.gnu.org/software/bison/     │
│ yajl        │ 1.0.8  │ 2.0.1  │ http://lloyd.github.com/yajl/          │
│ asciidoc    │ 8.3.0  │ 8.6.4  │ http://www.methods.co.nz/asciidoc/     │
│ xmlto       │ 0.0.23 │ 0.0.23 │ http://www.methods.co.nz/asciidoc/     │
│ docbook-xml │ 4.5    │ 4.5    │ http://www.methods.co.nz/asciidoc/     │
│ libxcursor  │ 1.1.11 │ 1.1.11 │ http://ftp.x.org/pub/current/src/lib/  │
│ Xlib        │ 1.3.3  │ 1.4.3  │ http://ftp.x.org/pub/current/src/lib/  │
└─────────────┴────────┴────────┴────────────────────────────────────────┘

 i3-msg, i3-input, i3-nagbar and i3-config-wizard do not introduce any new
 dependencies.

 i3-wsbar is implemented in Perl and has the following dependencies:

   • IPC::Run
   • Try::Tiny
   • AnyEvent
   • AnyEvent::I3

 All of them are available at CPAN, see http://search.cpan.org/
 Use your distribution’s packages or cpan(1) to install them.

 i3-migrate-config-to-v4.pl is implemented in Perl, but it has no dependencies
 besides Perl 5.10.