I’ve been fighting with these two e-commerce systems the last few days. I’ve never worked with either of them before, so it’s been a learning experience, to say the least.
What I have discovered is that I (and your experience may vary) can not stand Zen Cart. I liked the idea of it being free, and open source, and etc. etc. - but it’s just unusable. I had already designed what I wanted the store to look like and needed to go apply that design to their theme. It took hours and hours and I finally gave up. One of the biggest problems is that tables were so embedded into the “basic” design, that modifying anything meant screwing everything else up.
Then I gave Cube Cart a try - (which is free if you agree to keep their copyright notice at the bottom). First of all, it’s a store, I’m sure my client will have no issue paying the pretty minimal fee to remove the copyright - but before I ask them to shell out the money, I want to make sure that I can actually use the system, and apply the design. Which so far I’ve been able to do - mainly because their basic design is a CSS-based layout!! Not only that, the template files are easy to figure out and understand which one will do what. In just a few hours I’ve been able to get three times as far as I did futzing around with Zen Cart.
My only complaint is that I can’t find a comprehensive “tag” (or XML) list and/or a good tutorial on how to modify everything about the template. It’s been a lot of trial and error - and some of the things I wanted to do apparently require a mod (that usually costs money). Again, it would be nice to TRY some of them to see if it does what I want, but not all the mods have that same “try first - buy after” philosophy.
Still - modifying Cube Cart, even without a tutorial, had been infinitely easier than it was with Zen Cart. And the nice thing is that now that I’ve been working on modifying the Cube Cart pages for a little while, I feel a lot more confident about what I’m doing.
Update Well, I’m getting a little frustrated with Cube Cart. Ran into a few snags with shipping that I can’t seem to fix. Going to give either one or both LiteCommerce and X-Cart a try. If anyone has worked with any of these shopping cart packages - I’d love to hear what your experience is. Liked it? Loved it? Hated it? Prefer a different package? (if so why?) Feel free to link to a post on your own blog that talks about it.
Update 1/4/07: One of the things we wanted to do was have a “fixed/custom shipping cost” for the products (ie. not have it calculate shipping based on weight or whatever) - as well as not make it required for users to have to “register” in order to make a purchase… X-Cart apparently does both of these… Going to try to install their demo version and give it a test drive. I’ll keep posting updates on the progress…
Update 1/5/07: Well, heard a few horror stories about customizing X-Cart - as well I can’t even install their demo because of that Ioncube thing. Here’s a long list of other shopping cart packages. Eenee Meenee Minee Mo… /sigh
Update 1/7/07: Was considering Sunshop - but am now hesitating after reading this review. Next one up for review: Extcart / Avactis (are these TWO different packages? or the same one??)
Update 1/12/07: This has been quite the saga. I have tested out more shopping cart packages than I can count at this point. The ones that had the features I needed, had confusing templates. The ones that had easy to customize templates, didn’t have the features I needed. I’m not interested in writing my own. Whole companies are made out of just writing this type of software, and that is not the business I want to be in. So I took a look at Squirrelcart. I had originally dismissed them because they didn’t have a “demo/trial” copy I could install and play with. But at this point I was desperate. I looked at their online admin demo, and it appeared to have the features we needed. I asked their sales department for a sample template I could look at and they sent me one right away. There’s a lot of files, but they’re not completely confusing. The part that sold me was their documentation that outlines all the templates what they do and how to find the template you need to modify. As well, all the templates are pretty well commented so if there’s something showing up on your page and you want to find the template it came from you can just view source and it’s usually noted in the comments. I was told if I purchased the software I would have a 14 day evaluation period, so I bought it. I’m still in the process of customizing it for our client, but I’ve gotten pretty far in a fairly short amount of time. They don’t currently support the payment gateway we’ve signed on with, but I’m told they can add it. Still waiting to hear the final word on that. So far I’ve been pretty satisfied and would recommend them.
Update 1/16/07: I spent a big portion of the weekend tinkering around with Squirrelcart, and implementing our custom template for it and I’m still very pleased with it. I know there’s been a number of comments suggesting trying other carts, some of them I had tested and didn’t care for. I know Squirrelcart is missing some features some other packages have, but the important part is that it had what we needed. Should a client come along that needed one of those other features (that Squirrelcart doesn’t currently have), then I’ll probably have to look into some other packages, but in the meantime, I’m satisfied with what I got. In any case, feel free to keep the comments and suggestions coming. It’s always interesting to see what else is out there, and it will be good reference should I need to look for another cart in the future. 
IMPORTANT NOTE PLEASE NOTE THE DATES at which this post and comments were made. I have indicated the versions of the software discussed in this thread on this post (and summarized some of the comments as well - consider that one the “Cliff Notes” version of this very long thread).