Bolt is a very popular and powerful networking asset among Unity community. The recipe of its success resides in the abstraction of complex networking features behind simple and easy interfaces.
Bolt is now part of the Photon family. Frederik, (a.k.a. fholm), the creator of Bolt and the Photon team are heavily working together towards the release of Bolt v1.
Powerful Event System - Bolt has a built-in event system which automatically distributes the events to the correct receivers, highly configurable of course. Events can also be targeted at a specific game object or globally. Three delivery modes are available: Unreliable, Unreliable Synced and Reliable.
Authoritative movement - Built-in support for input and player controller state synchronization allows you to easily implement custom authoritative movement that suits your game.
Both dedicated and listen server - Bolt supports the classic dedicated server and also listen servers where the server is just another player.
Prioritization and scoping - Bolt supports both scoping of entities (which entities should a player be aware of) and prioritization of scoped entities (of two entities A and B that are scoped, which one is the most important for a player).
Hit-box recording - Bolt has built-in support for recording hit-boxes and rewinding and ray-casting against them, allowing you to implement complex techniques like lag compensation in first person shooters in just a few lines of code.
Synchronized map loading - Bolt supports loading maps from the server, have all the clients load the same map and then provide custom hooks telling the server when the client is ready and vice verse.
Supports all major unity platforms - Bolt runs on Windows, OSX, iOS, Android, and GNU/Linux. Xbox One, PS4, and Windows Phone 10 is planned.
Does not require Unity Pro - Bolt does not require Unity Pro for any platform and will run without problems on the free iOS and Android version of Unity.