The core/library submodule as provided by BuildCraft.
This submodule provides shared code used by other BuildCraft submodules, as well as some blocks/items shared between them (crafting component items, area marker blocks, etc). Notably, the mod's Wrench item is provided by this submodule, which is often well-supported by other mods.
Note that the BuildCraft project contains the complete mod in single-JAR format - but not all versions are available in this format; likewise, not all versions are available in this multi-JAR submodule format.
Licensing information is provided in the full version's description above.
