While "Speed Download" was a well-known download manager for macOS by Yazsoft, it has been for several years and is no longer officially supported on modern macOS versions.

The term is historically associated with software "cracks" or serial number generators (keygens) from the early-to-mid 2000s warez scene. Specifically, "BigSpender" was a common pseudonym for a release group or individual providing registration codes for Mac software during that era. Overview of Speed Download v5

Deep integration with browsers like Safari and Firefox.