One of my early PHP apps (initial version circa 2009).

At the time there simply wasn't an easy to use Wiki for non-techs.  My vision at the time was (and continues to be) to create a fully integrated suite of apps that prioritized easy-of-use within an attractive, engaging, & intuitive interface.  Why?  Because a system's usefulness is proportional to the amount of data input AND it's regular team input that counts.

The wiki pages allow user comments and have team-level access protection.  There's a code syntax highlighting version of this Wiki for software & IT teams.  This module is fully integrated into a back-office suite comprising 14 apps and full content-management-system.