Ragnarok World is a place where people can come in for the latest clients, support, guides, compiles, and not to mention if you are looking for a server to play. This place is to make users comfortable in setting up their own server and as well as provide help to one another.
As you've probably noticed above, the latest clients, along with lua files are available that are compatiable with the compiles I have posted above. Izunami is a custom rAthena compile that can be purchased for $25. More info is under the "Compiles" tab.
In addition a Judas's bible can be viewed on "Bible" link. Within it contains guides about how to setup servers and add customs. On the boards, you will find youtube videos that I've uploaded that further helps you get comfortable with setting up your own server!