XenForo

Discourse is a simple, flat forum, where replies flow down the page in a line. Replies are attached to the bottom and top of each post, so you can optionally expand the context of the conversation – without breaking your flow.

Flarum is the next-generation forum software that makes online discussion fun. It's simple, fast, and free.

It is an open-source knowledge-based community software. You can use it to quickly build your Q&A community for product technical support, customer support, user communication, and more.

It is designed to help teams inform, discuss, and make decisions at scale. For leaders at every level of a company, it is a platform for work that best delivers on decision making by tapping into the collective wisdom of an entire team, providing everyone with a voice to assure better business outcomes.

It is a modern community platform designed to live as an organic part of your existing website or product. Now you can easily create an engaged discussion space wherever your users already are - no more siloed external platforms or legacy forums!

Easily add sections. Create questions and answer them on the fly. Drag and drop and move things around. Edit everything in a flash.