WinISIS is a data-retrieval program sponsorized by UNESCO. It is freely distributed, it is used in the libraries all around the world (UNESCO distributes only the English, French and Spanish versions of the package, but user-developed versions exist in virtually all languages, including special versions which UNESCO helped in developing, for Arabic, Chinese and Korean).
In the migration to the Free/Libre OpenSource Systems, a big problem for the libraries that use WinISIS, is to migrate WinISIS too, and all their WinISIS records. A request to open the WinISIS code has been made, but there isn't a Linux version yet, and maybe waiting will be a bit long.
There are two official versions of WinISIS: 1.5 build 3 (the standard version) and 1.5 build 7 (the arabic version, by UNESCO and the League of the Arab States). The standard version is distributed in english, french and spanish version by UNESCO, but user-developed versions exist in virtually all languages, including special versions which UNESCO helped in developing, for Arabic, Chinese and Korean. All these user-developed versions can have some differences in the installation process.