LimeWire is a peer-to-peer file sharing client for the Gnutella network. It is free software released under the GNU General Public License. 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.
Written in the Java programming language, LimeWire runs on any computer with a Java Virtual Machine installed. To facilitate installation for casual users, installation packages are available for Microsoft Windows, Mac OS X, and in the RPM format for Linux. Support for Mac OS 9 and previous versions has been dropped with LimeWire 4.0.10. The Windows version of the LimeWire installer includes a version of Sun Microsystems' Java installer which will download and install version 1.5 of the Java Runtime Environment if it detects the machine does not have a recent version of Java installed.
LimeWire uses the SHA-1 and tiger tree hash cryptographic hash functions to ensure that downloaded data is uncompromised. Although researchers have identified possible vulnerabilities in the SHA-1 algorithm, because LimeWire does not rely on SHA-1 alone, these vulnerabilities do not have many adverse implications for LimeWire's verification of downloaded files.
If a user has iTunes on their computer, LimeWire can use iTunes to play downloaded music instead of LimeWire's built-in music player.
Lime Wire LLC, the developer of LimeWire, distributes two versions of the program; a basic, free version, which some consider illegal, and an enhanced version (LimeWire PRO) sold for a fee of US$18.88(£9.65) which as the developers claim offers faster downloads. This is accomplished by facilitating direct connection with up to 4 hosts of an identical searched file at any one time, whereas the free version is limited to a maximum of 2 hosts.[1] 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 open source, LimeWire spawned several free 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[3] states that some of LimeWire's open source contributors have forked the project and called it FrostWire. The FrostWire developers emphasize that they will never place any sharing-related restrictions on the client.