Txt2man is program that converts simple texts to manpages easily. The syntax of the ASCII text should looks like the output provided by man(1) program. So, you need write a text file using a visual approach of a manpage and txt2man will convert it. The txt2man(1) manpage is short and sufficient to understand how the program works.
A command to extract comments from source code (src2man) and a command to build an indexed volume from a set of manpages (bookman) are also provided by this package.
txt2man is very useful for programmers and Debian packaging.