Over the years, we have worked on a huge number of modules/plugins for Zencart which are mostly released freely as a way of contributing to the community.

Sales Boost

1. Ajax Onepage Checkout (aka XCheckout):  the checkout page is designed to keep your customers from being distracted. The whole process is divided into small steps to avoid overwhelming your customers with so much info to fill in and reduces cart abandonment rate.
2. Advanced Wishlist Manager: allows your customers to create multiple wishlists which they can decide share with others. Each wishlist item can be saved with personal comment/remark and price (at the time the item is added to wishlist) as well as desired quantity and attributes.
3. Products Comparison: your customer can line any product up against their other selections in one dedicated page, quickly allowing easy comparison between both attributes and product descriptions. In addition, any comparison that your customer creates can be saved directly to their My Account area for easy retrieval in the future, or shared with their friends via their social network of choice.