In reply to John Williams question about compressed files... The area of file compression and archiving is confusing, so I thought I'd post a short summary for those having trouble. This list is not comprehensive! I won't say much about Mac systems, except to say that Alladin's excellent Stuffit and Stuffit lite are more or less the universal standard - Mac users don't need any help..:-) Most problems are due to different operating systems and formats. Compressed files can either be single files or multi-file archives. Single file compression 1. UNIX compress Found in some archive, especially older ones. Proprietary protocol, thus now used less widely . Not recommended because of cross-platform troubles. File subscript: .Z (upper case - see gzip below) Create with: compress (UNIX or alternative OS implementation) Extract with: uncompress (UNIX or alternative OS implementation) gunzip (see below) Available: On UNIX systems, etc. plus proprietary things like the MKS utilities for DOS 2 gzip/gunzip The GNU alternative to compress. Originally a UNIX-based programme, now available on virtually every platform. Probably the file compressor of choice. Can extract UNIX compress (.Z) files. Freely available under the GNU license. Unfortunate name though - confusion with pkzip (see below)., which is an archiver. File subscript: .gz (lower case -now used universally) .z (lower case -dropped to avoid confusion with .Z) Create with: gzip Extract with: gunzip (or " gzip -d" - see documentation) Available: from a GNU site near you. Make sure you get the right version for your OS Macgzip is also available Archives 1. Stuffit for Macs (lucky people) 2. pkzip, etc. Proprietary archiver/compressor. Most PC users know about this one. Can hold one or more files. File subscript: .zip Create with: pkzip Extract with: pkunzip unzip (shareware) ......etc. - there are several others Winzip etc. under Windows provide nice interfaces and facilities (shareware) Available: PKware is widely available for purchase extractors are very widely available NOTE: self extracting archives can be created; these are .exe files 3. UNIX tar The original UNIX Tape ARchiver - does not compress, but allows files (and directory structures) to be placed in single file which may then be compressed. Not really of much interest to PC users, but you will find tar archives around - they usually mean the stuff in there is from a UNIX source. However, many programme source files (C, C++, etc) are held in such archives, so may be of interest to some. File subscript: .tar (often .tar.Z or .tar.gz when compressed) Create with: tar (tar -cf if you must ask) (or gtar) Extract with: tar (tar -xf........) (or gtar) Available: tar is on every UNIX system gtar is the GNU version, available from GNU sites/mirrors WARNING: tar archives are (usually) created under UNIX. This supports long file names and multiple occurances of periods (.) in filenames. The directory separator is a forward slash (/). If you try to extract a tar archive under DOS/Windows, the system won't like it. OS/2 tar (under HPFS) manages OK. There are other systems, including ZOO (.zoo suffix) and ARC (.arc). Not widely used now. A word of warning: some sites, for instance DEMON, don't always hold the latest versions of software like GNU, so it worthwhile going to the original site or a mirror that aims to keep up to date. That's why I use sites like LEO, despite it being slow (OS/2 only, I'm afraid - sorry I can't suggest good Windows mirrors) Hope this is of help >>>>>>>>>>>>>>>>>>>>>> Andrzej Glowinski [log in to unmask] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%