IOTA is a distributed ledger technology that uses a structure called the Tangle to maintain a tally of token ownership between multiple nodes. This structure allows for newer transactions to verify older ones, bypassing the bottleneck caused by blockchains. The IOTA protocol is in research and has two public networks: the IOTA mainnet, which manages tokens, and Shimmer, which tests protocol updates. The IOTA was founded in 2015 by four co-founders, including David Sønstebø and Dominik Schiener, who currently serve as co-chairmen of the board of directors. One of the co-founders, Sergey Ivancheglo, resigned in 2019 but continues to provide advice as an unofficial advisor.