This is my emacs configuration, placed on github for portability and general sharing. It has accumulated a decent amount of cruft over the years, so please feel free to point out where it can be improved.
These days I have a fairly homogenous environment across my different installations, so there's not a lot of effort put in to making things backwards-compatible. I mostly run a snapshot build on a Linux (Ubuntu) host, and the latest build on windows. Most configuration should be portable, but there are facilities to load platform-specific (and host-specific) code when necessary. I assume a very recent Emacs.
This should be as simple as cloning from github. If you check out to
~/.emacs.d then you are finished. Otherwise, you can place it
where-ever you feel like and just symlink init.el to ~/.emacs; it
is designed to be portable like this.
I use use-package now, after years with el-get. There are a couple of helpers for packages that are only on github, or sometimes at a URL (which I host on gists).
The top-level file is init.el; it basically just adds its parent
directory (which should be where you checked this out) to the
load-path, and loads a bunch of mode- and task-specific files. These
are by convention named custom-<task>.el, mainly so they will be
grouped together in a directory listing. The exception is the
allowance for platform-specific initialisation, which is loaded by
looking for a file with the same name as the symbol-value of
system-type.
For efficiency, I have borrowed a few hints from
Jacob Gabrielson's post on effective emacs,
in particular setting things up for autoload where possible, and as a
result making heavy use of eval-after-load. This might occasionally
make it a bit harder to read.
There's a bit of defensive coding; in place of (require 'foo)
followed by configuration, I tend to use (when (require 'foo nil t) ...) instead. The last argument to require means to simply return
nil but not signal an error in the event that a feature cannot be
loaded. Yes, this all could and possibly should be wrapped as a
macro.
Look at https support for package.el