Shopp Improved

Shopp Improved is a plugin that extends the popular
Shopp eCommerce solution for WordPress.
You must have the Shopp
Plugin in order to use this plugin.

I recently worked on a site where I used the Shopp WordPress plugin to set up
E-Commerce. The first big issue that I ran across was allowing for user
customizations of products. For example, if a product can be engraved with a
name, includes the person’s initials, can include a message, etc. Shopp does
include the ability to add these kinds of user input fields, but it’s done
through a template tag. This means that you either have to apply it to all
items, or you need a developer to set it up on a per-product basis. My client
has quite a few products that are custom-made, and they really needed to be able
to set up these fields themselves.

In comes Shopp Improved. It creates a user interface to allow you to easily add
these fields to any product. The inputs can then be easily integrated into a
shopp product template with just a couple lines of code.

Requires PHP 5+.