Other additional plugin-like feature sets, called Layers, are optional and not required to be a valid Marble contract, but do add exceptional capabilities on top of the Marble Core Interface.
Named content trackers that can hold any string based content, and also a method to store the content checksum and the algorithm used to produce it.
Named key/value pairs that can be assigned to individual Marble Items to represent any kind of numerical value.
A pre-built set of tags and attributes that can be applied to an Item all at once. Created and updated by group managers.
The Events layer provides a set of features for capturing, logging, and saving timestamps.
The Backings layer allows for Items to be backed with fungible currencies that transfer with ownership. All backings are released to the owner upon destruction of the Item.
The Vouchers layer includes features for creating redeemable vouchers of varying types and values.
The Boxes layer adds functionality for batching Items for various purposes. Items placed in boxes are unable to be transferred until removed from the box by the box owner.