How LimeWire Works


­LimeWire provides a gateway for users to share software and music.
­LimeWire provides a gateway for users to share software and music.
Image courtesy of LimeWire

It all began with Napster. As the music industry watched, millions of strangers logged on to the famous file-sharing site to swap MP3s for free. In 2003, the original Napster was shut down by a copyright infringement lawsuit, but it was too late to put the genie back in the bottle. The world had tasted the power of peer-to-peer (p2p) file-sharing, and it wanted more.

Next came Gnutella, a new kind of p2p network. Gnutella differs from Napster because it doesn't have central servers that store information about which files are being shared. Gnutella isn't a Web site or a software download. It's a network protocol -- a standardized system of queries and responses that allows individual computers to talk directly to each other.

For more information on Gnutella-based p2p file-sharing, read our article How Gnutella Works.

LimeWire is hugely popular. By December 2007, it had been installed on 18 percent of Windows PCs worldwide [source: TorrentFreak]. But the same controversy that surrounded Napster -- the illegal downloading of copyright material -- now plagues LimeWire, even though LimeWire cautions its users against sharing songs and videos that are under copyright protection.

In August 2006, the music industry sued LimeWire for enabling and promoting "Internet piracy" of copyright-protected music and video [source: Cnet]. LimeWire insists it's a software tool for legally sharing non-copyright files. The case is still pending.

In this HowStuffWorks article, we're going to walk you through the basics of using LimeWire, look at some advanced features like LimeWire Pro, share troubleshooting tips and answer the question: Is LimeWire really legal?

Let's start with LimeWire basics.

Installing and Using LimeWire

­Users can save files and create organizational folders.
­Users can save files and create organizational folders.
Image courtesy of LimeWire

Here's how to install LimeWire on your computer:

  1. Download the installer program from the LimeWire Web site. You have a choice of downloading LimeWire BASIC (free) or LimeWire Pro ($21.95).
  2. Open the downloaded file to launch the Installer Wizard
  3. Follow the steps to install LimeWire in the appropriate folder on your PC.
  4. Once the installation is complete, you'll enter the Setup Wizard.
  5. Indicate the folders you wish to share with the Gnutella network. You have the option of letting LimeWire search your hard drive for all media files.
  6. Give LimeWire permission to pass through any firewalls on your computer and local network.

Before you can download the installer program, LimeWire asks if you'll use it for "copyright infringement." If you answer "yes," you'll not be allowed to complete the download.

Once the installation is complete, launch LimeWire and take a look around. The program will always open to the Search Tab. At the screen's top left corner are search categories for different types of media files: Audio, Images, Video, Documents, Programs and All Types.

When you click on one of these search categories, it'll open customized search fields in the window below. Under Audio, for example, you can search for song title, artist, album, genre and license type. You can check the "More Search Options" button for advanced search fields like track number or song length.

At the bottom left side of the Search Tab window is a button that says "What's New." Click the What's New button to see the latest files that have been added to the Gnutella Network under each search category. If you don't know what to search for, it's a good way to see what's fresh and popular.

Press Search and the search results will begin to fill up the main part of the Search Tab window. Depending on your connection, it may take a couple of minutes to find all of the related files on the network. Results are listed from most popular (more copies of the file available at higher download speeds) to least popular (fewer copies at slower download speeds).

Double-click on a file to begin downloading it. If LimeWire can't find a license for the file, it'll ask if you want to cancel the download or proceed without a license. The file will then appear in the Downloads window at the bottom of the screen, along with a progress bar showing the percentage of the file downloaded and from how many hosts.

Once the file is downloaded, it'll appear in your library. Click the Library Tab at the screen's top. Click the Saved Files folder on the left side of the Library window to see all the downloaded files. Within Saved Files are subfolders for different media types (audio, video, et cetera).

Double-click on any file in the Library, and it'll be added to the Playlist at the bottom of the Library window. Use the LimeWire Media Player controls at the bottom right of the screen to pause, stop and play audio files in the Playlist. Other file types will be launched in their associated media player or software application.

Now let's look at some advanced features of LimeWire, including LimeWire Pro.

Other Features and LimeWire Pro

­LimeWire Pro offers advanced features and technical support.
­LimeWire Pro offers advanced features and technical support.
Image courtesy of LimeWire

LimeWire contains several features for monitoring your connections on the Gnutella Network. Under the View menu at the screen's top, go to Show/Hide and choose Connections. The Connections tab shows to which computers you're connected on the Gnutella Network. You have the option of adding or removing connections as well as browsing the shared folders of a particular computer.

Click the Monitor tab at the top of the window to see which files are being downloaded from your shared folders and by whom. These are called uploads and are listed in the Uploads section at the bottom of the Monitor window. You can press the Kill Upload button to stop another user from downloading a particular file. At the top of the Monitor window is the Incoming Searches box, which shows the most recent search keywords entered into the Gnutella Network.

You can even chat with other users on the Gnutella Network. Click on one of your connections in the Connections tab and hit the Browse Host button at the bottom of the screen. Right click on one of the files on the host's computer and choose the "Chat with Host" option. You can also right-click on any file in your search results to chat with that file's host.

Another useful LimeWire feature is filtering. Go to the Filters menu and choose Configure Content Filters. If you check the Enable Content Filters box, LimeWire will compare all downloaded or uploaded files with a list of copyright content supplied by the entertainment industry. All content on that list will be filtered from your search results.

Also in the Filtering menu are options for Junk, Keywords and Hosts. Under Junk, you can increase the sensitivity of LimeWire's automated junk filter, either removing all junk from search results or just keeping it at the bottom of the results list. Keywords allow you to filter out search results containing certain words. There are also check boxes for filtering out adult content and certain types of files that could contain viruses (.html, .vbs, .wmv and .asf). The Host option allows you to enter the IP address of a specific host to ban them from sending or receiving queries from your machine.

LimeWire is now integrated with iTunes, the popular digital music software. Any songs you download through LimeWire will automatically appear in your iTunes library. You don't even have to re-launch iTunes.

LimeWire Pro is an upgraded file-sharing service offered for a one-time charge of $21.95. According to LimeWire, LimeWire Pro searches out more connections, giving users 66 percent more search results with every query [source: LimeWire]. Increased and better connections mean faster downloads.

LimeWire Pro users also get access to free tech support and free software updates for six months. Regular LimeWire users don't have access to tech support, relying instead on message boards and forums.

Now let's look at some troubleshooting tips for common problems with LimeWire.

LimeWire Tips

Users can select their connection speed such as broadband or DSL.
Users can select their connection speed such as broadband or DSL.
Image courtesy of

The most common problem with LimeWire is a failure to connect to the Gnutella Network. Here are a few different ways to figure out whether or not you're connected to the network:

  • In the bottom left corner of the LimeWire screen are a set of connectivity bars. The more green bars, the better the connection. If you have only one green bar, you're not connected.
  • If you go to the Connections tab and all your connections are shown as "connecting," then there's something wrong.
  • If you conduct a search, but no results appear, even after a minute, then there's a connection problem.
  • If you see an icon next to the connectivity bars showing a globe behind a brick wall, then you're behind a firewall This usually isn't a problem for LimeWire, but you should double-check just in case.

Connectivity problems can be caused by several factors, which you should check in the following order:

  1. Open a Web browser and make sure you're connected to the Internet. If not, unplug and restart your Internet modem and any routers that are connected to it. If that doesn't work, you should call your Internet Service Provider. Once you've regained Internet connectivity, reopen LimeWire and try again.
  2. Try disconnecting and reconnecting to LimeWire. You can do this either by quitting and re-launching the program, or by going into the File menu and choosing Disconnect, then Connect.
  3. Popular Internet security programs like Norton, McAfee and ZoneAlarm can interfere with LimeWire's ability to connect to the Gnutella Network. You need to go into the settings of your firewall software and add LimeWire as an exception.
  4. You should also check any hardware firewalls, either on your computer or a router. The important information to know is through which port LimeWire communicates. Under the main LimeWire menu, go to Options, open the Advanced tab and click on Firewall Config. Take note of the "Listen on Port" number. Go into your computer or router firewall and assign that port number to LimeWire.
  5. Finally, check with your ISP or your system administrator if you're at work. Some ISPs and office networks block p2p file-sharing programs.

For those who only want to download non-copyright material, you have the option we mentioned before of filtering any content already on LimeWire's list of copyright files. Another legal tip is to only search for files with an open license. When you search for audio, for example, there's an option to show songs carrying the freely distributed Creative Commons or Weedshare licenses.

Another common complaint is that files download too slow. LimeWire's answer is that a file can't download any faster than the maximum bandwidth of either the uploader or the downloader. If you have broadband, but the person you're downloading from has dial-up, the file's going to download at dial-up speed. Also, if you're downloading more than one file at a time, or the host computer is uploading more than one file at a time, that's going to put a strain on bandwidth as well.

The best tip for speeding up downloads is to only choose files from high-bandwidth hosts and preferably more than one host. One of the features of p2p networks like Gnutella is that they can download pieces of the same file from many different hosts at once and reassemble the whole file on the downloader's computer. Downloading a song from eight high-bandwidth hosts should take less than 30 seconds.

If that doesn't help, you could always upgrade to LimeWire Pro, which promises faster download rates, or try one of the many third-party applications that claim to do the same.

OK, now let's explore whether or not LimeWire is really legal.

Is LimeWire Legal?

LimeWire's file-sharing service lets users exchange software and music; users must sign an agreement saying they'll respect copyright laws.
LimeWire's file-sharing service lets users exchange software and music; users must sign an agreement saying they'll respect copyright laws.
­Image courtesy of LimeWire

LimeWire, the software application, is completely legal. What many people do with LimeWire -- namely downloading and distributing copyright material -- isn't legal.

LimeWire's defense is that its software is a tool. Like any other tool, its use is dependent on the users. The same hammer that helps build a house can be used to break the back window and rob it. The person who sells the hammer can't be held responsible for how it's used. Right?

In August 2006, several large record companies sued LimeWire for encouraging Internet piracy. They're asking for $150,000 for each song distributed without permission of the copyright holder [source: Cnet]. A week earlier, the makers of Kazaa, another popular file-sharing application, settled with the music industry for $115 million and installed special filters on its software to block copyright material. As of this writing, the case against LimeWire is still pending.

Even if LimeWire is found not guilty, its users are still vulnerable. Since September 2003, the Recording Industry Association of America (RIAA) has initiated lawsuits against more than 20,000 individuals for alleged illegal file-sharing [source: Electronic Frontier Foundation].

The accused individuals receive a letter from the RIAA's lawyers with a settlement offer to avoid going to court. The individuals are identified by their IP addresses. If the individual refuses to pay the settlement -- typically between $3,000 and $11,000 -- the RIAA threatens to sue them by name for a larger amount [source: Electronic Frontier Foundation].

Even with the RIAA's legal assault on software companies and individuals, the number of active worldwide file-sharers continues to grow. And if LimeWire gets shut down tomorrow, there are already dozens of other programs poised to take its place.

Now let's take up another important question: is LimeWire safe?

Is LimeWire Safe?

LimeWire's filters protect users against potential unsafe files.
LimeWire's filters protect users against potential unsafe files.
Image courtesy of LimeWire

The Federal Trade Commission (FTC) has issued a consumer alert citing safety issues associated with p2p file-sharing. Here are the FTC's two main concerns when using file-sharing software like LimeWire:

  • You may accidentally share files on your computer that you intended to be private.
  • You may unwittingly or unknowingly download copyright material, pornography or viruses.

LimeWire responds to these concerns by educating users on how to protect themselves and their children from accidentally sharing or downloading the wrong files.

  • Shared folders - You can control which folders and files are shared with other users of the Gnutella Network. If you're unsure of which folders are being shared, go to the Library tab and click on the Shared Files folder on the left side. If you see a folder or file you don't want to share, you can press the delete button to remove it.
  • Pornography - Go to the Filters menu and choose Configure Content Filters. Click the Keywords button and check the box that says Ignore Adult Content. This activates LimeWire's Family Filter that examines and discarded files that may contain adult content.
  • Spyware and Viruses - LimeWire proudly states that its software is spyware free, meaning that the company doesn't bundle third-party advertising software with its product. However, LimeWire warns against downloading files with a .exe, .vbs, .lnk, .bat, .sys, or .com extension because they could contain viruses or spyware. In the content filter, you can check a box to remove all such files from your search results.
  • Shutdown and Startup - The FTC warning includes a recommendation to shut down file-sharing programs when you're not using them. In the Tools menu under Options (or on Mac, the LimeWire menu under Preferences), you can click on the System Tray tab to choose default shutdown behavior. LimeWire can either shutdown immediately or wait until all active downloads are done. In the same menu under the Advanced tab is a section for System Startup. Here you can decide whether you want LimeWire to launch automatically upon turning on your computer or not.

Now let's take a quick look at the future of LimeWire.

The Future of LimeWire

LimeWire's users can select their settings and can share files they select.
LimeWire's users can select their settings and can share files they select.
­Image courtesy of LimeWire

Lime Wire LLC, the New York-based parent company of LimeWire, is looking to capitalize on the success of the file-sharing program and expand the reach of the LimeWire brand.

Next up is LimeSpot, a new online social network, now in beta version. LimeSpot, like other online communities, will allow users to create a personal profile page, host blogs, write wikis and make "friends" with other LimeSpot users.

Plans for the online store, which isn't yet operational, include buying songs directly from LimeWire search results, plus a standalone LimeWire Store Web site. LimeWire currently has licensing deals with two independent music distributors, IRIS Distribution and Nettwerk Productions.

Establishing a legal online store could be a way to stay alive if LimeWire loses its copyright infringement lawsuit with the RIAA [source: Cnet]. For now, LimeWire still appears to be concentrating on improving its p2p service and offering more features like BitTorrent support.

We hope this HowStuffWorks article helped you understand more about how LimeWire software works and the controversy around p2p file-sharing. For more information on file-sharing, Gnutella and related topics, see some of the links on the next page.

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