I once spent some time writing a small package manager for Emacs.
http://gmarceau.qc.ca/plugin.el
I wrote:
Plugin is my attempt at creating a
package manager for Emacs. Plugin
will automatically downloads Emacs
extensions, unpacks them in a
directory, adds that directory to the
load-path, generates auto-load
annotations, and modify your dot-emacs
file. The auto-load annotations are a
little-known feature of Emacs. Once
they are generated, Emacs extensions
load quickly and incrementally, which
is really nice if you have as many
extensions installed as I do.
You will need two library files to get it to run, loop-constructs.el and record.el
