>Now I use pkzip and pkunzip programs i my applications . I'm looking for library for VFP

I use WinZip in my apps, whenever I need to do something. Its not fully automatable, so if what you need is not to intense, it will most likely do (check out the WinZip command line utility for command line control, used with Ed Rauh's LaunchAppAndWait() in API_APPRUN it does everything I want).