When we talk about open source software we are of course referring to the ones that apply to this industry. So this would include software like Wordpress, Joomla, Wordpress and others that people use to manage their website. But the answer to the question is, it might be right for you.
When you look at the websites for this software you will see some large names that use their software, but don´t be fooled. What these companies have is not the same version as what you will download, or at least it is not any more. What these companies do is download the foundation software and then they put thousands of hours into modifying it to fit their needs. So what you have, and what they have are two completely different things. They use it as a foundation to save time on doing a lot of the base work, not as their complete solution. The question is, will this work for you?
Often times we also talk to people that have had their website designed in something like Wordpress. We are huge fans of that software, just not as a website development tool. It was designed with a very specific purpose in mind, which was blogging and it is awesome for that. As a website design or even as a business tool, it just isn´t cut out for the job. Wordpress is the equivalent to a single module that most complete website design companies use. It is designed to be an element of your website, not what your website is built in. Does it work for what you need it to do? Well, if you cut of the roof of your sedan, take out the back seats and open it up, you can use that as a pickup truck. Will it work? Yes it will, will it be as good or as effective as a pickup truck. Well, we think you know that answer to that question.
The bottom line is, that open source software can be great if you use it for what it was designed to do or if you are using it as a foundation for further development. All the yare designed to do is to cut down development time on the base that you will be using. Then it relies on people sharing further developments they may have done, the problem once again, it is like buying random car parts and hope they fit as spare parts for your car.
As a final thought, if something goes wrong with your open source website, if there is an error, a hiccup or a problem, who is responsible for fixing it?