FlashGet
FlashGet is a leading download manager. It uses MHT(Multi-server Hyper-threading Transportation) technique, supports various protocols and has excellent document management features. 100% Clean, free.

• Easy to install and use
• Call anti-virus automatically to clean virus, spyware and adware after finishing download.
• Optimize the system resources - uses up the lowest system resources and will not influence your normal work or study.
• Powerful files management feature
• Increase the download speed and stability
• Support HTTP、FTP、BT and other various protocols
• Win9x/Me/NT/2000/XP/2003

FlashGot is an extension for integrating FlashGet and Mozilla Firefox. FlashGot is the free Mozilla / Firefox / Flock / Thunderbird extension (compatible with Netscape too), meant to handle single and massive ("all" and "selection") downloads with several external Download Managers. FlashGot turns every supported download manager in a download manager for Firefox! It is available on Mozilla Update. Note that some antivirus software may incorrecly claim that it has a virus, as it uses Visual Basic Script (.vbs) files when integrating with Internet Explorer.
(Thanks Giorgio Maone.»)

FlashGet Opera Plug-in also available.

Fresh Download
Turbo charges downloading files in FTP, HTTP and HTTPS protocols using your current internet connection (dial-up, cable, DSL / ADSL, satellite, T1, etc). Internet Explorer, Mozilla Firebird and Firefox, Netscape Communicator, Opera, Avant Browser, Crazy Browser, Maxthon / MyIE2, Slim Browser, in any Windows operating system (95, 98, Me, NT, 2000, and XP). Simply grabs any URL from these popular browsers and Fresh Download will take over.


Star Downloader
Star Downloader supports FTP and HTTP. Proxy is also supported. Also integrates with your antivirus program to automatically scan files upon completion of the download. The clean and simple interface of Star Downloader and the multilingual support for over 50 languages makes it easy for everyone to use! Star Downloader works on all Windows systems after and including Windows 95. For example: Windows 95/98/Me/NT/2000/XP; Mozilla, IE, Netscape.


Free Download Manager (FDM) is a full-featured download accelerator and manager. Easily download a list of files and whole web sites from any remote server via HTTP, HTTPS and FTP. For Microsoft Windows 9x/ME/2000/2003/XP/Vista (build 6000). FDM is a light-weight, powerful and easy-to-use application. Also this software product is well-known for its intuitive and user-friendly interface. FDM can function as a site manager, accelerator, site explorer and scheduler.


LeechGet
The Personal Edition is completely free for non-commercial use. Full Internet Explorer integration; Plug-Ins for Mozilla and Opera users are available. Integrates into Windows 9x/2000/XP. A lot more features that a comfortable Download Manger simply *must* have.

Oribit Downloader
Orbit Downloader is a super light and free rich media downloader. It is based on p2p and multi-source downloading technology and supports HTTP, HTTPS, FTP, MMS and RTSP protocols. Support HTTP, HTTPS, FTP, MMS and RTSP and Proxy. Orbit Downloader can download up to 500% faster with great acceleration. 100% free and no registration allowed. Microsoft Windows 9x / ME / NT / 2000 / XP / 2003 / Vista. Support Internet Explorer 5.0 and above, support FireFox 1.5 and above [include FireFox3(Gran Paradiso)], support Opera and Maxthon.


TrueDownloader
An open source download manager/accelerator with good features like Pause/Resume downloads, simultaneous downloads, segmented downloads for acceleration . Both HTTP and FTP protocols are supported , and it's very fast ! You can even improve it or adapt it to your needs since it's open-source. Some special features like HTTP/FTP Proxy support and ZIP previewing are supported too. Integrates flawlessly into Internet Explorer, Mozilla and FireFox thanks to the Extension Technology. Compatible with Windows 95, 98, ME, 2000, XP !


Urlgfe
Urlgfe is an open source download manager. It allows you to classify URLs before downloading them, and allows you to import URLs from HTML files. Every category has an independent configuration that can be inherited by each download in that category. Operating System : 32-bit MS Windows (NT/2000/XP), All 32-bit MS Windows (95/98/NT/2000/XP), All POSIX (Linux/BSD/UNIX-like OSes), Linux, Win2K, WinXP.


wxDownload Fast
wxDownload Fast (also known as wxDFast) is an open source download manager. It is multi-platform and builds on Windows(2k,XP), Linux and Mac OS X(binary still not available). Besides that, it is a multi-threaded download manager. This means that it can split a file into several pieces and download the pieces simultaneously. All 32-bit MS Windows (95/98/NT/2000/XP), All POSIX (Linux/BSD/UNIX-like OSes), Linux, OS X. User Interface : Cocoa (MacOS X), Gnome, KDE, Win32 (MS Windows). Calculates the MD5/SHA1 checksum of downloaded files so they can be easily verified

Portable edition - Windows only.

ConnectFusion Download Accelerator
ConnectFusion Download Accelerator is a very fast, open source download manager. It will accelerate your downloads from the Internet and resume broken connections. It includes an easy-to-use interface and its installation does not interfere with the normal behavior of your browser. ConnectFusion Download Accelerator is 100% free, never expires, and does not contain any spyware or advertisement. Its source is freely available to any one who wants to inspect or modify it. Windows Platform : Microsoft Windows 95, 98,Me, NT 4.0, 2000 ,Win XP or later.


DownThemAll
dTa is a popular, ‘multipart download’ download manager/accelerator extension for Mozilla Firefox. DownThemAll is completely free and open source. It can increase download speed up to 400%. It can pause and restart downloads at any time, without losing data, and enables users to quickly download all the links, images or embedded object contained in a webpage with a single click. It also uses fully customizable criteria to let you get only what you really want from a page. Both HTTP and FTP protocols are supported. if your OS supports Firefox, then you can surely run dTa.


Net Transport
Net Transport (NetXfer) is a fast, powerful downloading tool.
Protocols: HTTP/HTTPS/FTP throughSSL/SFTP/MMS/RTSP/Bit Torent

Net Transport is a closed source software download manager and stream ripper. It is also known as NetXfer. Lately, Xi, the company which Net Transport is associated to, started to include FTP Transport, which is similar to Net Transport, with Net Transport install file. So far, as in September 2006, there are two types of NetXfer: Unicode and ANSI. You can read more overview of NetXfer at the official site listed above. With Firefox, of course, use at flashgot. Supported OS: Win95 / Win98 / Win98SE / WinME / WinNT4 / Win2000 / WinXP / Win2003

Version 1.87 was released as freeware and is available at OldVersion.com.
The latest versions are released with a 90 day trial version. Afterward, the program is still functional, but there is a nagging screen to buy the program after the trial period has expired.