In this chapter we learned about the disadvantages of an open system and advantages of user accounts. We have also learned how we can customize MediaWiki based on our preferences. We have learned about problems that can occur in the multi-user environment of a wiki site. We also learned about preventing such problems and resolving edit conflicts. We discussed how to create a discussion page and communicate with other users. So we know all aspects of creating a multi-user wiki site using MediaWiki. In the next chapter, we will start learning about administering MediaWiki, where we will require at least a little knowledge about PHP. So before you start the next chapter, have a review of your PHP knowledge.