There are many things related to the conference, which sometimes are done by different tools:
- Attendee registration (payments, pre-paid attendees, scholarships)
- Handling of accommodation issues (price, rooms, who shares with whom, multiple accommodation sites)
- Program - submissions, review etc. This is can be handled by software like EasyChair or Pentabarf. The output should be ready to use program (but then you need rooms, timeslot management, etc.)
- Wikimania has also scholarships - there is an application form and review process by the committee