6 IDM alternative on Ubuntu :
A download manager is a computer program dedicated to the task of downloading (and sometimes uploading) possibly unrelated stand-alone files from (and sometimes to) the Internet for storage. Some download managers can also be used to accelerate download speeds by downloading from multiple sources at once.
1)- DownThemAll :
DownThemAll lets you download all the links or images contained in a webpage and much more: you can refine your downloads by fully customizable criteria to get only what you really want.DownThemAll is all you can desire from a download manager: it features an advanced accelerator thatincreases speed up to 400%, it allows you to pause and resume downloads at any time and, last but not least, it's fully integrated into your favorite browser!.
2)- Xtreme Download Manager :
Xtreme Download Manager is a powerful tool to increase download speed up-to 500%, resume broken/dead downloads, capture FLV videos from any site and schedule downloads.
3)- uGet :
uGet is a lightweight and full-featured Download Manager for Linux and Windows. uGet allows you to download in multiple parallel streams for download acceleration, put files in a Download Queue, Pause & Resume downloads, Advanced Category Management, Browser Integration, Clipboard Monitoring, Batch Downloads, localized into 23 Languages, and many more features.
flareGet is a full featured, multi-threaded and multi-segment download manager and accelerator for Windows and Linux.
5)- aria2 :
aria2 is a lightweight multi-protocol & multi-source command-line download utility. It supports HTTP/HTTPS, FTP, BitTorrent and Metalink. aria2 can be manipulated via built-inJSON-RPC and XML-RPC interfaces.
6)- Axel :
Axel tries to accelerate HTTP/FTP downloading process by using multiple connections for one file. It can use multiple mirrors for a download. Axel has no dependencies and is lightweight, so it might be useful as a wget clone on byte-critical systems.
That's all enjoy ;)