mget <URL> [output file name]
This software depends on curl utility.
mget check for content length and make several parallel streams, which download parts of target content. By default target file is devided into 100Mb chunks.
In test I downloaded 1.7Gb ISO file in approximately one minute, while in single mode it was doanloaded in six-seven minutes.
There is no error control at all. Please check final data integrity with checksums.