This post is written for a client who wants a website and is either deciding if they should use Joomla as a foundation for the website, or a third party is proposing to use Joomla and they are wondering if that's a good idea. I'll discuss the pros and cons and also a few things to look out for.

What is Joomla?

The about page on joomla.org describes it the best. Here's a short quote: "Joomla is an award-winning content management system (CMS), which enables you to build Web sites and powerful online applications. Many aspects, including its ease-of-use and extensibility, have made Joomla the most popular Web site software available. Best of all, Joomla is an open source solution that is freely available to everyone." See http://www.joomla.org/about-joomla.html for more information.

Pros

Gives You Control

Joomla is a content management system, which means that your site will largely be content driven. The most common scenario is that a webpage displays an article or a group of articles. Joomla provides very nice, easy to use tools for writing and editing articles. So, if you want to edit the content on a certain page, it will likely be as easy as it would be to open a Word document and change a sentence. If you want to make a whole new page, it will likely be as easy as creating a new article and possibly also creating a new menu item to link to that article (which Joomla also makes easy). Parts of the site that are not based on articles can also be edited, however the complexity will vary.

Using Joomla also gives you control of who develops your website and who maintains it for years to come. Because Joomla is popular and open, many people know it. The complete opposite end of the spectrum would be a developer that suggests you use their proprietary CMS or some other proprietary software. This makes you dependent on them. You won't experience that with Joomla. If it makes sense for you at some point to use a different developer or even if you decide you want to hire developers and maintain your website in-house, it will be easy with Joomla.

Out-of-the-Box Extensions, Some Free

Joomla has a large collection of extensions for Joomla. Some are free and most that are not are pretty cheap. One of the huge selling points of Joomla is that it is so popular and that popularity is the reason that there are so many extensions available. Depending on your technical aptitude, you may be able to install some of these yourself. It's not very dangerous to try, so in general you can feel free to give it a shot and only get help when you get stuck.

Save Money

It is easy for you to edit your site and therefore it's easy for your developer(s) too. Instead of building everything from scratch, the developer is sometimes able to get a lot of functionality out-of-the-box. The more specific and tricky your requirements are, the harder it will be to make out-of-the-box solutions work.

User Friendly

There are other solutions out there that are similar to Joomla, such as Drupal. So why choose Joomla? I'm not going to dig very deep on this, but one strong point of Joomla is that the administrative interface (where you'll edit articles, for example) is very easy to use. It is likely that you'll be able to figure out the basics without reading any documentation.

Cons

Learning Curve

While Joomla is easy to use, you're still going to have to take some time to get comfortable with it. Some people may prefer to just have a web developer take care of everything. However, in my experience, most people like the option of having some control. Joomla gives you the option of editing your site on your own, but you can certainly still get help.

Square Peg, Round Hole

To put it simply, if Joomla doesn't handle a certain requirement well, your developer may end up spending a lot of time trying to hack Joomla. Honestly, Joomla is pretty flexible, so I don't think this will often be the case. But it is something to consider and it should be considered by someone who knows Joomla well. In other words, make sure you get a developer that knows Joomla well and thoughtfully considers if Joomla is right for you. You don't want a developer that is dependent on Joomla because that is all they know.

Considerations

Communicate What You Want To Edit

Your whole site won't be editable just because you use Joomla. The developer has some control over how much of your site you'll be able to edit, so if there are parts you really care to edit, communicate w/ them about that. On the flip side, if there is something you don't care to edit, might want to make sure they don't bill you for time making it editable.

Knowledge Transfer

Some things to learn about your site are generic to Joomla, some are specific to how the dev built your site. Whoever develops your site will need to at least document how they put the site together and especially the non-standard things they did. The rest of Joomla, you can learn yourself. However, it might still be nice to get a basic introduction. So make sure you discuss how this knowledge transfer will go down.

Make Sure You Can Install Extensions

Often when you set up Joomla, there are permission problems that prevent the client from being able to install extensions. If you plan on getting your hands dirty and trying to do things on your own with your website, then ask your developer to be sure that these permissions are set up right.