There are other systems for software documentation. We cannot say whether it belongs to the user-oriented or developer-oriented group about neither one of them. Every one of them was created with a certain particular aim, which it has followed. These contain: PerlDoc man info PerlDoc is a documentation system used by the community around a script language Perl. The thing that helped its growth is the existence of CPAN - archive of reusable code for Perl. The documentation is written straight into the source code using special POD marks. Users then access it using Perl system script perldoc. There are many converters of PerlDoc documentation into different output formats, including HTML. The documentation system of system manual pages (man pages) has been created in the times of creation of the operating system UNIX and is actively developed to these days. To format the output, we use the nroff program and pages are displayed with the man command. They come along on almost every UNIX or GNU/Linux system. Every man page is compressed and saved on the disk separately. There are tools for its conversion to other formats. The result of the GNU movement (GNU is not UNIX) is info documentation, which is trying to substitute the man pages. This documentation system is not being used as much as its creators would expect due to its complicated control and user-unfriendly look. However, most of the GNU tools still includes more detailed documentation in its info pages than in corresponding man pages. The pages can be displayed with the info command.