Third-party Software

Third-party software generally falls into the following somewhat overlapping groups.

Commercial software products are developed, distributed and maintained under a licensing agreement with a vendor or organization, generally for a fee. Commercial software products are normally installed like the vendor supplied software, but in a separate directory.
The author of a software identified as shareware, would normally expect some payment for downloading the software and accompanying documentation. The payment is often voluntary and made to a specified organization.
According to the 'Free Software Foundation', freeware is a software that everyone is free to copy, modify and redistribute. The word "free" pertains to freedom. It does not imply that it is free of charge, so anyone can sell free software so long as they don't impose any new restrictions on its redistribution or use. GNU software is an example of the freeware. The right to redistribute the software is legally bound with the condition that the distribution include original code, complete documentation including the changes made.
Total absence of copy right protection is the characteristic of public domain software. Any one can copy, modify or use it in any way the wish. The author has no exclusive right and has no legal responsibility associated with the use of the software.

Archive sites

Publically accessible software, including shareware and freeware, may be accessed via anonymous FTP or the WWW from an archive site on the internet. A network search utility named archie may be used to search databases of Anonymous FTP host directories and locate specific software.

Some well-known archive sites in USA include the GNU archive site and UUNET. Popular busy archive sites often may have mirror sites which keep copies of specific directories or files to make them quickly available to local users and to reduce the load on the original site. For example, ftp.uwsg.indiana.edu/pub mirrors several popular software distributions including, gnu, linux, mosaic, netscape, perl5, and sendmail.

Installing Third-party Software

Software distributed over the network will often have the suffix .tar.Z or .tar.gz. The suffix .tar indicates the file is written using the tar utility, and the suffix Z would indicate that the tar file is compressed using the Unix compress utility whereas the suffix gz indicates the file compression using GNU gzip utility. Therefore to extract the files from a software distribution, the tar and uncompress or gunzip utilities are required. The error message "Checksum" during the uncompression often indicates problem with downloading the package. Make sure that 'binary' mode is selected for ftp transfer.

A software distribution may include pre-compiled and packaged binary executable modules for specific operating systems. A list of FTP sites which distribute software ported to a specific platform may be found on the UWSG home page.

If the software distribution includes only the source code and documentation, it is necessary to build the executable machine code specifically for your operating system. The process normally includes compiling and/or assembling the source code, linking with appropriate libraries, moving the files to appropriate directories and testing the installation. In general, all software distribution will include the files; README, INSTALL, and Makefile. The Makefile will have the necessary instructions to build the library (if one is necessary), the executable module, and the documentation. Most systems come with a make utility required to process the Makefile. The files README or INSTALL will have the necessary instructions to install the product on each system to which the product is ported. Unix tools, imake and xmkmf, distributed with the X window system are quite useful in generating a Makefile specific to a platform, taking into account the machine dependencies, such as compiler options, alternate command names, and special make rules.

Terms used: Anonymous FTP, mirror site, GNU, GNU archive site, checksum, compiler, assembler, make, makefile, imake