For a general overview of unroff and a description from the user's perspective, please read the manual page unroff(1) that accompanies the distribution. In addition, there exists one manual page for each output format for which a back-end is provided, and another one for each combination of output format and troff macro package explaining the translation rules associated with the individual macros. For example, the back-end for the Hypertext Markup Language (HTML) that is part of the distribution and that supports the -man and -ms macros comes with these manual pages:
unroff-html(1) unroff-html-man(1) unroff-html-ms(1)
This text assumes familiarity with the basic troff and Scheme concepts. For a troff manual, refer to the documentation provided by your UNIX system's vendor. As unroff supports a number of troff extensions introduced by the free groff formatter (which is part of the GNU project), you may want to read the manual page troff(1) that is included in the groff distribution.
unroff is centered around Elk, the Scheme-based Extension Language Kit. For a description of the Elk-specific Scheme language features please refer to the documentation included in the Elk distribution (which is freely available). An overview of Elk can be found in: Oliver Laumann and Carsten Bormann, Elk: The Extension Language Kit, USENIX Computing Systems, vol. 7, no. 4, pp. 419-449, 1994. The Scheme language is described in several textbooks; and the Revised^4 Report on the Algorithmic Language Scheme, on which the IEEE Standard for Scheme is based, can be downloaded from several major FTP sites.