For last several months i have been working on two most used e commerce frameworks in open source Opencart and Magento
There are lot of comparisons are available between two saying which one is strong and flexible about support and other factors.
I would like to add some thing on this topic too
First I came across opencart framework around year back, at that time I was new to any framework, so started exploring and got a totally new experience.
within a couple of mins i m ready with default framework options with some sample data a full working admin a nice template and working e commerce site.
After couple of days I showed it to my seniors and they asked me to prepare a demo for diamond trading site. I have no reference in hand just a basic three page design.
home page category page and details page.
I searched for some content on web for diamond related thing and came up with http://naturaldiamondcompany.com
On this we got couple of more projects to do, and i become familiar with opencart. Such a simple framework, you dont have to do much to explore, and also if u need to change some functionality
the code is open and easy to modify
Few days later for some project the client is specifically asked for magento, another e commerce framework.
I downloaded next day and you dont believe it took around two days to understand the installation process and set up the default functionality
After week too i m struggling to set up the common options like category products reviews shopping cart etc
Its too horrible, another thing what i came across it not accepting localhost as the default host name, you need to provide the local IP address in the config file for admin to work
An explanation given by experts that its for live domain and for localhost
Another huge issue i got with database shifting from local to live, It took me around one hour to check where is damn config file for database
where in opencart its much simple in the main folder for admin and for front end u will get the config file with simple variables
Another issue with magento is bulk upload product say around 50k or 100k or more dynamically via script, It took me around two days to find out the exact database structure where magento insert the data
In couple of forums i got solution to use the magento default controller via Mage.php file and use the insert method with parameter assign and use it in loop
I thought the problem is solved but the script took horrible time to insert the products in bulk. I checked with fewer products it loaded fine but as the count increased the time increased exponentially
For opencart it took around 10 mins to understand the product database and i build the script in less than two hours for the first time and inserted the 100k records in less than two mins.
When it comes to customization of both the framework Opencart community always helped me a lot with quick response where in magento i got suggestions to use paid modules for the same functionality
Following image will explain you in detail characteristics of each of them