Abbrevia is a compression toolkit for Delphi, C++Builder, Kylix, and Free Pascal.
It supports compressing and decompressing PKZIP, Microsoft CAB, tar, gzip, and bzip2 archives, and can create self-extracting executables. On Windows it also provides Delphi wrappers for the LZMA, Bzip2, and WavPack SDKs, and PPMd decompression.
Abbrevia also has several visual controls that simplify displaying and manipulating archives, including treeview and listview components.