I'm not aware of any batteries-included frameworks, but here are some of the p2p-ish libraries that I've either worked with personally, or looked into and found promising, along with some commentary:

Telehash: http://telehash.org/

Provides a p2p-capable messaging stack. I've worked with an earlier version (v2) for Toc Messenger [1]. V2 included an integrated DHT for public peer discovery along with the p2p messaging stack. Was actually surprisingly robust and reliable considering how young the project was at the time.

V3 seems to have pivoted towards the private mesh networking side, and spun out the DHT into a separate project, but V3 itself doesn't seem to have a clear story for integrating with an external, public DHT the last time I checked, so the intended use cases aren't quite the same as V2.

[1] http://toc.im/

Matrix: http://matrix.org/

Doesn't allow for fully peer-to-peer messaging, but is decentralized and federated like XMPP. Probably the closest thing on this list to a framework (handles both messaging and storage).

Last time I looked at it, my main concern was how much implicit trust users needed to place in homeserver providers (messages and user profiles are stored in plaintext). Unless this has changed, I don't find it viable for any app that values user privacy. Even federated networks eventually gravitate towards a large degree of centralization once the tech becomes mainstream (see email). If any servers are used at all in a privacy-minded app, they need to be zero-knowledge as far as I'm concerned, for actual user data at the very least, if not metadata as well (I realize the latter is an unsolved problem).

RemoteStorage: https://remotestorage.io/

A decentralized, federated protocol and library for data & file storage. Also used this for Toc. Worked as advertised but I'm looking to explore fully p2p alternatives for my next project.

The main problems I ran into (asides from the non-fully-p2p architecture) was the rather clunky API (for instance, it requires developers to provide a schema to fully specify objects they want to store, but doesn't provide a versioning and migration mechanism to take advantage of the schema specs, although it is planned), and the fact that encryption for data at rest wasn't implemented (until I finished working on a custom encryption layer for Toc built on top of the library).

Kinto: http://kinto.readthedocs.org/en/latest/

Similar to RemoteStorage, but decentralized discovery is planned and not implemented yet. It's built by Mozilla and apparently used in Firefox and Firefox OS (I'd assume for Firefox Sync?).

They also have a comparison table with RemoteStorage as a part of their docs if you're interested in a more detailed (but possibly impartial) comparison [2].

[2] http://kinto.readthedocs.org/en/latest/overview.html#compari...

Swarm: https://github.com/gritzko/swarm

A decentralized data replication library that's built on ops-based CRDTs [3]. Some very impressive work here. Although I recently found out that V1 of the library no longer supports fully p2p replication due to architectural changes, which made it a lot less interesting for my use cases.

[3] https://en.wikipedia.org/wiki/Conflict-free_replicated_data_...

Replikativ: https://github.com/replikativ/replikativ

The one I'm most excited about personally. Similar to Swarm, a CRDT-based data replication library, but even more ambitious (they envision an open data exchange whereby users fully control their own data, and can specify any number of applications to have access to that data, instead of the status quo where user data is kept in closed, per-application silos). There's a comparison with other alternatives, including Swarm, in their README [4].

They also plan to have pure browser-based p2p replication through WebRTC, which is exactly what I'm looking for.

It's built in and for Clojure and ClojureScript, but JavaScript support is in the works. As if I needed any more incentive to get started on my first ClojureScript app. =)

[4] https://github.com/replikativ/replikativ#alternatives

GunJS: http://gun.js.org/#step1

A decentralized, replicated graph database. The pitch is very impressive sounding, but I'm hesitant to actually use this because they promise a lot of replication magic, but the replication is built on a home-grown algorithm rather than something rigorously peer-reviewed and implemented industry-wide like CRDTs.

I'd love to hear from anyone who has actual working experience with it though.

IPFS: https://ipfs.io/

IPFS and its suite of associated libraries has already been mentioned elsewhere in this thread, so I won't elaborate on it.