cabextract is Free Software for extracting Microsoft cabinet files, also called .CAB files. It is distributed under the GNU GPL license and is based on the portable LGPL libmspack library.
cabextract is released at https://www.cabextract.org.uk/
libmspack is a library for some loosely related Microsoft compression formats: CAB, CHM, HLP, LIT, KWAJ and SZDD.
libmspack is released at https://www.cabextract.org.uk/libmspack/