DragonAPI 1.7.10 is a function library and support mod which is relied upon by all of Reika’s mods. If you do not have the API, you will crash on game load with a NoClassDefFoundError mentioning DragonAPIMod.class.
If you are a developer, here are some of the features to using DragonAPI:
How to install:
DragonAPI 1.7.10 Download Links:
For Minecraft 1.5.2
For Minecraft 1.6.4
For Minecraft 1.7.10