Applejuice is a semi-centralized peer-to-peer file sharing network similar to the original eDonkey network. A peer-to-peer (or P2P) computer network is a network that relies on the computing power and bandwidth of the participants in the network rather than concentrating it in a relatively few servers. ... File sharing is the activity of making files available to other users for download over the Internet, but also over smaller networks. ... The eDonkey network (also called eDonkey2000 network or ed2k) is a file sharing network used primarily to exchange music, films and software. ...

Topology

The Project offers Server- and Clientsoftware for Applejuicenet. This means, the network is not managed by one company/organisation/server, but decentralized over many servers. The servers however, are a central point for all users.

Users of the Applejuice client connect to an Applejuice server, search for and find files, also locate files with a given hash from links, and then download them directly from other clients (or "peers").

For locating resources, the Applejuice network uses a Client-Server system. However, the Servers are also connected one to another, so if you are on a Server A you can locate files from users on the Server B (Server-Server). If you located one User downloading a specific file, the Users also exchange other known sources which they got from servers or users (Client-Client).

The topology is comparable to IRC. Clients have to connect to a server, so it is centralized and Client-Server, however, there are many Servers for one network, and there are also many networks as everyone can host a server for a new one. Client-Client would be DCC :)

Network

The Servers don't store any files. All files are served by the Clients. The Servers will index these files, and the Clients will exchange the files. The Clients are actually Servents (P2P), regarding file sharing services. The used terms describe the role in the file searching services. In general a servent is a peer-to-peer network node, combining functionalities of a server and a client. ...

The network is based on credits. Clients which made much content available can use the so called "Powerdownload" which will shorten the waiting in queues and increase download rates.

Structure of Client

The Client consists of 2 elements:

• Core - the part which will do all operations, written in Java
• GUI - a graphical user interface (C++,.NET,Java,PHP,Linux,..)

The elements are connected over a network (TCP/IP). The Core listens on a specific port, and the GUI connects and gets status information/sends requests.

The protocol for communication between core and GUI is open. Every application which implements it can be used as GUI. Currently, there are native Windows GUIs, an official Java GUI, a PHP-Webinterface and also a Linux-based GUI.

The core also runs without a connected GUI. Thus, you can close the GUI and go on swapping, or also shut down your local computer if the core runs on a server.

Usage

The Applejuicenet is used for content distribution with a given Hashlink. The system has also a built-in search to search servers for keywords, however this feature is not widely used and also not very efficient. Instead, Community Linksites exchange hashes and some information about the file, then enter this hashlink in their client.

Miscellanious

There is not much information available about it in English, but a lot in German, as that is the language of most of the developers and users.

External links

• Applejuice homepage in German
• Applejuice forum in English