CON Suite is (intended to be) a comprehensive, free, open source, WordPress plugin for planning and managing Conventions/Conferences/Convocations/etc... "Cons"
Why? Because cons need lots of planning. Most of the software out there is a poor fit at best, buggy, or expensive. Some of the best ticketing software will hold the money till after the event is over. Sometimes weeks after. This is not a good thing for new cons where the pre-=sale ticket money is used to make the down payment on the hotel or for other expenses.
What is it? It's a WordPress Plugin. It helps you plan and manage your con.
Where did it come from? It came from me, the webmaster of Changing Times Changing Worlds. There were things I wanted to automate, but there was no one tool that could do them all... in fact, the many tools I used were buggy, incompatible with eachother, and worse, hard for the people who needed to use them to understand. This comes from my own wishlist started after CTRCW2014 and really gets to be important after CTCW2015.