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.
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. From version 4.8 onwards, LimeWire works as a UPnP Internet Gateway Device controller in so far that it can automatically set up packet-forwarding rules with UPnP-capable routers.
LimeWire offers the sharing of its library through Digital Audio Access Protocol. As such, when LimeWire is running and configured to allow it, any files shared will be detectable on the local network by DAAP-enabled devices (e.g. iTunes).
- LimeWire limits queries to 3 - 30 characters. This is to prohibit searches for specific files. This limitation also means that the network will return more results than necessary. 
- LimeWire does not forward SHA1 searches. SHA1 searches find exact copies of files. [[Magnet: URI scheme|Magnet]] links use SHA1 searches. SHA1 searches can also be used to find more sources for a download.
- Like all Gnutella clients, LimeWire uses SHA-1 and tiger tree hash cryptographic hash functions to ensure that downloaded data is uncompromised. Researchers have identified theoretical weaknesses in the SHA-1 algorithm. A 'vulnerability' in SHA1 suggests that it may, at some future time, be possible to crack SHA1, which would allow files to be spoofed (mis-described) on the network. In practice bogus search results are more problematic. 
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$24.95 that offers faster downloads. 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.
According to a June 28, 2005, report in The New York Times, Lime Wire LLC was considering ceasing distributing LimeWire due to the outcome of MGM v. Grokster. On September 25 2005, it was reported that Lime Wire LLC was working on a version of the program which will refuse to share files that lack valid license information. Neither of these events occurred, and as of Template:Today, it is still possible to download LimeWire and share copyrighted files.
On August 4, 2006, the Recording Industry Association of America (RIAA) sued LimeWire, alleging that it was profiting from unauthorized downloads. On September 25 2006 LimeWire countersued the RIAA for antitrust violations.
On September 7 2007, Gregory Thomas Kopiloff of Seattle was arrested in what the U.S. Justice Department described as its first case against someone accused of using file-sharing computer programs to commit identity theft. According to federal prosecutors, Kopiloff used LimeWire to troll other people's computers for financial information and then using it to obtain credit cards for an online shopping spree, federal prosecutors said. 
LimeWire, LLC generates its revenues from the sale of LimeWire Pro, and items such as t-shirts and caps, which display the Limewire logo. A LimeWire Pro license costs $24.95, and provides the user with a 6 month license to download updated Pro versions. A 1-year "Extended Pro" license is available for $34.95. While commonly mistaken by many users to be a license to the content accessible via LimeWire on the Gnutella network, in fact, it is only a license to the software. However, the Pro version is readily available from alternate sources including the Gnutella network (for example, a user may use the freely-distributed version of LimeWire to find and download the Pro version).
The Pro version differs from the Basic version in 4 respects:
- It offers personalized technical support.
- It provides more search results by connecting to 5 UltraPeers instead of 3 UltraPeers.
- It comes with extra skins, including a special "pro only" skin.
- Its downloads are "turbo-charged"
- "Advanced Peer-Based Technology Business Models". MIT Sloan School of Management. 2002. http://shumans.com/p2p-business-models.pdf.
- Silverthorne, Sean (2004). "Music Downloads: Pirates- or Customers?". Harvard Business School Working Knowledge. http://hbswk.hbs.edu/item.jhtml?id=4206&t=innovation.
- LimeWire search limits.
- Felten, Edward W (2004). "SHA1 Break Rumored". Freedom To Tinker Discussion Forum. http://www.freedom-to-tinker.com/archives/000661.html. Retrieved 2005-07-08.
- Content Pollution and Poisoning
- "FrostWire Beta Released", from Slyck.com
- Tom Zeller. June 28, 2005. "Trying to Tame an Unruly Technology". New York Times. Section C, Column 2, Pg. 1.
- http://recordingindustryvspeople.blogspot.com/2006/09/lime-wire-sues-riaa-for-antitrust.html and http://recordingindustryvspeople.blogspot.com/2006/11/limewire-files-amended-counterclaims.html
- BBC News: Warning on search engine safety
- LimeWire Official Website
- LimeWire Official Blogs
- LimeWire linked to Identity Theft
- LimeWire Bears Brunt of Identity Theft Concerns