If you run a website, or have build a software application, you’ll need to have a certain amount of interaction with your users. One of the best ways to facilitate that is through forums. Forums not only allow seamless communication between users and developers, they also let companies provide support for their users. On the Internet, you’ll find millions of forums dedicated to various issues. From teenage problems to geriatric care, forums bring people with similar tastes or issues together and let them communicate effortlessly.

One of the best things about forums is that they have been an indispensable part of the FOSS (Free and Open Source Software) culture. Be it the then-fledgling Ubuntu forums that helped desktop neophytes with installations and troubleshooting or the WOW forums that brought millions of gamers together, forums have been an integral part of the Internet since its inception.

For a FOSS lover though, everything should be open source and free as in freedom. So, forums too, for us, need to be in that open realm. If you are looking for the best free and open source forum software for your site, here is the big list:

phpBB is one of the most popular open-source forum software out there. Written in PHP, this free tool supports multiple database engines and lets you extend it using various plugins and tools. phpBB has a huge community backing it and has been used widely by many software publishers and website owners. Currently in its third major version, the forum software comes with a modular design, high-security, and a multiple-language interface.

Feature-wise, very few software come close to phpBB. It comes with features like attachments, styles, data management, search system, notifications, and also caching.

On the security front, phpBB comes with various anti-spam features like CAPTCHA confirmation, flood warning, post approval and more. You can even mark a post or a private message as spam.

Vanilla Forums is one of the coolest and the most stylish forum software around. It gives you nice-looking forums that are more community-based rather than being just tools for user support. You can customize your forums with various themes and also measure engagement by using statistics. Unlike phpBB wherein you get a plain-looking forum, Vanilla gives you a lot of control over the appearance, allowing you to make your forum site really look good. What’s more, there’s an official iPhone app for the software. Worth a try if you’re looking for something cool and new to try out.

OSQA is a free and open-source software forum that is more suited for FAQ-style forum. You can create a forum that is similar to AskUbuntu or StackOverflow with this software. OSQA gives its users points and badges based on their interactions and their contributions to the community.

bbPress comes from the makers of WordPress. It is an open-source forum tool that is both easy to set up and simple to use. More than just creating a forum, with bbPress you can create an entire social network. If you’ve worked with Wordpress.org or .com before, you’ll find bbPress very easy to use.

miniBB is a free and lightweight forum tool for building your own forum. More often used by small-site owners and bloggers, it can serve as a great discussion board for a selected number of users. You can even test the forums at this page: http://minibb.org/minibb-test.php?

Though miniBB doesn’t offer anything aesthetically pleasing, it is, nonetheless, one of the best forum tools if you’re looking for something simple and lightweight.

If speed is your priority, then FluxBB might be the right one for you. Light, user-friendly, and of course, fast, FluxBB comes with a clean admin interface and easy installation and setup. Once installed, you can modify permissions very easily. Also, FluxBB supports both PHP4 and PHP5, allowing it to be installed on most of the web servers. Another notable feature of FluxBB is that it is very secure as compared to other forum software, making it a great choice for new users as well as experienced ones.