Zen Cart started in 2003 as a spin off from the OsCommerce code and has had a few major releases since the inception. Currently Zen Cart is on version 1.39, but they have Zen Cart 2 in the works. However Zen Cart 2 has been talked about for almost 2 years and the BETA version has still not been released. Despite the slow progress on updating to Zen Cart 2, the current Zen Cart version 1.39 is still a solid choice for those wanting to use free shopping cart software. The great thing about Zen Cart is that it has a long history in ecommerce, so most hosting companies offer applications to allow for a one button install of Zen Cart. This method is preferred as you do not have to worry about setting up databases on your own, but if you know PHP and MySQL then you should be able to handle installation on your own. Dreamhost is a good example of a quality hosting company that uses a simple 1 button install to help customers quickly get set up with a free shopping cart from Zen Cart.
There are a number of benefits in going with a trusted open source solution like Zen Cart as your pick for free shopping cart software. Overall Zen Cart is a great choice for anyone needing free cart software, as there is an extensive amount of documentation online if you get stuck or have questions. Since this is free shopping cart software, you do not have any sort of dedicated formal help as you would with other paid ecommerce software solutions. However there is a strong Zen Cart community and forum where you can find answers you need or ask questions to get specific answers not addressed. Although Zen Cart is a free cart software, it still has a strong product management system to allow merchants to properly run an ecommerce site. In terms of free shopping carts, Zen Cart has one of the best product management systems which even accommodates reviews, coupon codes, gift certificates, tax and shipping rules, and even set sale and clearance rules. There are also a number of free templates which merchants can use with Zen Cart, as well as paid templates if you want something even more unique. Another plus with Zen Cart is that you can export your data to QuickBooks, which is very common among ecommerce store owners.
Zen Cart does offer quite a few robust features, but utilizing all of these features is not easy if you don't know PHP. The backend admin panel is not intuitive and for many can be overwhelming due to the small text and abundant options. You must know code to customize Zen Cart beyond simple color changes, or pay for an already customized template that you can then tweak to meet your needs. Getting a Zen Cart template would also be a great option for your customers, because the default template isn't the most user friendly for visitors to your site. Sometimes, you will find bugs where certain actions on your site won't work properly, so if you are a merchant that needs some hand holding from an expert, you would be better off finding a paid ecommerce solution.
The bottom line is that Zen Cart is a robust free shopping cart solution, but it is best suited for those with PHP or MySQL development skills. This is because the free cart software can be limiting without advanced knowledge of those programming languages which will allow for further modifications and customizations. Hopefully the release of Zen Cart 2 will bring about changes so that this free shopping cart appeals to a wider audience.