XNap

XNap is an exceptional Java plugin-based peer-to-peer (P2P) framework and client, which is highly recommended for both developers and end-users alike. The P2P technology has evolved significantly in recent years, and new network protocols are developed on a regular basis with new applications for P2P technology continuously emerging. However, developers often don't want to concern themselves with making the technology available to a broader user community, instead, they prefer to concentrate on the implementation of the core technology. This is where XNap comes in, aiming to bridge this gap by providing programmers with easy-to-use interfaces for common tasks such as search, transfer, and collaboration.

XNap aims to provide the greatest common denominator, and most of the interfaces are straightforward. This framework supplies resuming, chat, hotlist, and a media library, and provisions are taken to ensure the API also enables protocol-specific extensions. Due to the extension API, it was possible to write a plugin for the Gnutella network using the Limewire core within a single weekend.

Another benefit of XNap is its modern Swing-based user interface and console support that run smoothly on various platforms with a recent Java Runtime Environment (1.3 or higher). The XNap client is also created in a way that allows easy extension through plugins, and all of the network protocol implementations are provided by plugins. Some of these plugins are merely front-ends for existing network protocol implementations.

XNap has various features that make it stand out amongst the multitude of P2P applications available, including connection to multiple networks, multiple concurrent searches, plugin architecture, auto-resume of incomplete downloads, bandwidth throttle support, leecher blocking, buddy list, socks and HTTP proxy support, integrated file preview, per-user download and upload control, Emacs key bindings, auto completion, search and command history, auto-update to the latest version, fine-grained result filter, integrated command line, and Mac OS X integration.

Overall, if you're looking for a reliable P2P framework and client that can connect to multiple networks, operate multiple concurrent searches, and support various protocols, then XNap is the perfect choice. Its plugin architecture and extension API also enables developers to easily and quickly integrate their technologies into the network, making it both an enjoyable and exciting experience for everyone involved.