Decentralized storage service Sia has been around since 2014, originally incorporated as Nebulous Inc.
Sia launched their Cryptocurrency by the end of 2015. Early investors have since seen an incredible increase of the currencies value by over 18.000 times the initial price. Before launching their Cryptocurrency a Whitepaper was published with details on how Nebulous/Sia expected to see the network grow, describing their storage capacity algorithm and more.
Sia uses smart contracts to ensure SLAs on uptime, pricing and more. Sia is open source and written in Golang.