Pillar is a mod that allows pack developers, players and server owners to create custom world generation structures using 1.10's new Structure Blocks.
This mod is server sided, which means it does not need to be present in clients if your server wants to run it.
You can find a guide on how to use the mod over here.
If you made any cool structures using Pillar that you want to share, I recommend putting them in the World Gen category of CurseForge's Customization section.
If you have any problems with the mod or just want to contact me, you can find me on Twitter (@Vazkii) or IRC (#vazkii on irc.esper.net).