The question is pretty hard to search in search engines. All the time I try, only links to some Linux libraries documentation are found.
I am actually looking for something else - some library in Linux that to provide help files browsing API, like in WinHelp or MS HTML help . The idea is to have the help in some common format - html or something (and why not .chm), and to be able to call this library in order to display some topic of the help file.
The API must provide search in the help files by keywords or topic names. It will be a great if the Windows help files (.hlp or .chm) can be converted to this system formats.
I know there are man pages in Linux. But they are not suitable for my needs. Only GUI based systems please.