We are targeting the end of 2019 for the initial release of Polkadot.
Polkadot is currently undergoing a series of proof-of-concept testnet releases as new features are completed and rolled out.
- PoC-5 (Release date TBD) - Interchain message passing (ICMP), BABE block production, Parachain auction module
- PoC-4 (Release date 3 April 2019) - Staking changes and GRANDPA optimizations Release Blog post
- PoC-3 (Released 21 Dec 2018) - GRANDPA finality gadget added, Testnet: "Alexander" Release Blog Post
- BBQ-Birch testnet (Went live: 15 October 2018): Added smart contract support.
- PoC-2 (Released 29 Jul 2018) - Support for parachains added; rewards and slashing added to PoS consensus algorithms. Testnet: "Krumme Lanke". First automatic upgrade via governance. Release Blog Post
- PoC-1 (Released 16 May 2018, Testnet went live 18 May 2018) - Initial proof of concept - included basic state transition engine for relay chain and on-chain governance. Release Blog Post
For latest information on the state of the Polkadot roadmap and the Polkadot codebase, please see the Polkadot GitHub repository, specifically the milestones page: https://github.com/paritytech/polkadot/milestones