Installing Emacs on BSD
Emacs is available on the BSD variants either through precompiled binary packages or user-compiled ports. Installation instructions vary according to exact OS.
FreeBSD
To install the most recent prebuilt binary package of the (at the time) most recent stable version:
# pkg_add -r emacs
Or use the ports to build from source:
# cd /usr/ports/editors/emacs && make install
Developers may find "Using Emacs as a Development Environment," from the official FreeBSD project documentation, a good starting point. Some of the config tweaks are a bit dated and might need updating. But overall it's a reference
OpenBSD
Set PKG_PATH to an appropriate mirror.
# pkg_add -i emacs
pkg_add will prompt you for which version you want—currently, versions 21, 22, and 23 are available.
You can also install from the ports tree; however, "The [OpenBSD] ports tree is meant for advanced users. Everyone is encouraged to use the pre-compiled binary packages."(OpenBSD FAQ, section 15.3)
No premade port or package for Emacs 24 seems to be publicly available currently.
NetBSD, DragonFlyBSD, other pkgsrc systems
On systems using pkgsrc, something like
# cd /usr/pkgsrc/editors/emacs && make install
should work.