Currently 7z is the best file compressor there is but there is no good component in Delphi
Jedi JCL however uses a very old version of DLL and does not support the newer versions of 7z.
For commercial use Delphi's native zlip is very slow and generates a very large compact file for a 3gb database or higher.
several components like "Zipmaster" and "ziptv" no longer exist.
they use their own algorithm which I consider a waste because they are slow and also generate a very large compressed file compared to 7-zip