At the time this milestone was created, 0x Mesh is a P2P node that stores, validates, and shares 0x orders.

(1) It has a WebSocket endpoint for submitting 0x orders to the network,
(2) It performs 0x order validation and orderbook pruning.
(3) All relevant state is persisted to disk so that the node can trivially restart from where it left off after a crash.
(4) It uses FloodSub as a pubsub mechanism.

Before the beta can be considered complete, we must still add:

(1) Peer discovery (currently you must manually add new peers).
(2) WeijieSub (a more incentive-compatible and more efficient pubsub mechanism).
(3) A way to subscribe to order events via the WebSocket API.
(4) Tracking ETH reserves for orders stored (we have already implemented efficient ETH balance updating; it's just not currently used when storing orders).
(5) Full browser support (some components are already browser-ready, but others are not).