The Nxt platform developers are still working on the Ardor platform. As more transactions are completed on the blockchain, the amount of data recorded grows; yet, the amount of data that a full node requires to function becomes increasingly dense.
The sequence of transactions grows longer over time, causing the Blockchain to slow down. Updates will not solve the problem at its source. Furthermore, Blockchains are not adaptable to diverse applications and must be maintained over time.
Ardor's structure consists of one primary blockchain (Ardor) and a number of offshoot blockchains. This primary blockchain has been programmed to allow for quick and simple transactions. Child blockchains may be built in a matter of hours, and they can issue their own coins.