If you are selling crocheted cell phone covers from your kitchen table, you can build your online store using a point-and-click solution from providers like Yahoo, Amazon or eBay. If you have a team of software developers sitting around idly after finishing their back-end business model, you’ll probably be inclined to build your e-commerce solution from scratch. If you’re anywhere in between, you might be tempted to investigate cart software.

Cart programs cost a few hundred to a few thousand dollars and provide a database schema and system data, lots and lots of dynamic pages in a tag-based development language (ASP.NET, PHP, ColdFusion, etc.), and some HTML/CSS skins for modifying the look of the site. Ease of installation is emphasized: Choose an installation directory, provide your database credentials and stand back. Once the generally massive installation scripts are done, you will have a public-facing store and an internal-facing administrative interface. From that stage, you’ll be able to get to “Hello, e-commerce” very quickly.

The allusion to the classic “Hello, World” program was intentional, since cart software should not be viewed as a stand-alone application but rather as a domain-specific language (DSL).

If you are in any way serious about your e-commerce solution, your store must encode some domain knowledge. If you sell chickens, your store has to know about eggs and feed; if you sell rocket engines, you have to know about heat and pressure. The encoding and expression of that domain knowledge are what will determine your Web store’s success.

The administrative interface to your cart software will not look very language-like. The “just fill out a few forms” look can fool you (or the predecessors whose work you have to refactor—the more likely scenario for SD Times readers) into defining your products in a haphazard manner. Almost all cart software allows you to create custom fields (such as nib weight or rocket-fuel compatibility) and generally makes it easy to add some “validation JavaScript” (i.e., business rules).