LimeWire

LimeWire is a peer-to-peer file sharing client for the Java Platform, which uses the Gnutella network to locate and share files. Released under the GNU General Public License, Limewire is free software. It also encourages the user to pay a fee, which will then give the user access to LimeWire Pro.
Features

Written in the Java programming language, LimeWire is able to run on any computer with Java Virtual Machine installed. Installers are provided for Microsoft Windows, Mac OS X, and Linux. Support for Mac OS 9 and other previous versions was dropped with the release of LimeWire 4.0.10.
Limewire offers the sharing of its library through Digital Audio Access Protocol. As such, when LimeWire is running, any files shared will be detectable on the local network by DAAP-enabled devices (eg. iTunes).

Limitations

LimeWire limits queries to 3 - 30 characters. This is to prohibit searches for specific files. However, this limitation means that the network will return more results than necessary. LimeWire doesn't forward SHA1 searches. SHA1 searches find exact copies of files. Magnet links use SHA1 searches. SHA1 searches can also be used to find more sources for a download. LimeWire uses SHA-1 and tiger tree hash cryptographic hash functions to ensure that downloaded data is uncompromised. Researchers have identified possible vulnerabilities in the SHA-1 algorithm. All Gnutella clients have this limitation. In practice bogus search results are more problematic. Versions

Lime Wire LLC, the developer of LimeWire, distributes two versions of the program; a basic version for free, and an enhanced version sold for a fee of US$18.88 (£9.78) that offers faster downloads, though you can download the Pro version of Limewire off of the basic version for free.[citation needed] This is accomplished by facilitating direct connection with up to 10 hosts of an identical searched file at any one time, whereas the free version is limited to a maximum of 8 hosts. Prior to April 2004, the free version of LimeWire was distributed with a bundled program called LimeShop (a variant of TopMoxie), which was considered by computer security experts to be spyware. Among other things, LimeShop monitored online purchases in order to redirect sales commissions to Lime Wire LLC. Uninstallation of LimeWire would not remove LimeShop. With the removal of all bundled software in LimeWire 3.9.4 (released on April 20, 2004), these objections were addressed.

Being free software, LimeWire has spawned several forks, including LionShare, an experimental software development project at Penn State University, and Acquisition, a Mac OS X–based Gnutella client with a proprietary interface. Researchers at Cornell University developed a reputation management add-in called Credence that allows users to distinguish between "genuine" and "suspect" files before downloading them. An October 12, 2005 report states that some of LimeWire's open source contributors have forked the project and called it FrostWire.
LimeWire was the first file sharing program to support firewall-to-firewall file transfers, a feature introduced in version 4.2, which was released in November 2004. LimeWire also now includes BitTorrent support.
Source: http://en.wikipedia.org/wiki/LimeWire