I'm not sure how difficult this would be to implement, but it would be very useful ...
Sometimes I end up invoking joe just to view a file with syntax highlighting, without actually editing it. In other words, I use it as a replacement for a pager like less(1). However, I like the navigation and other features of less(1) much better, as far as simple viewing (not editing) is concerned ... So what I really want is to somehow teach less(1) to use joe's syntax highlighting.
One way to do that would be a special option to joe (lets call it “-pager”) that causes it to not enter edit mode, but simply print the given file(s) to stdout with syntax highlighting applied, i.e. plain text with ANSI color escapes. Then I could write:
joe -pager somefile | less -R
To save typing, you would create an alias or shell function:
jess () { joe -pager "$@" | less -R ; }
so you could just type “jess somefile” ... et voila. (Another solution would be to use the pre-processor feature of less(1) by setting LESSOPEN="||-joe -pager %s" or similar.)
The nice thing is that you could combine it with a different pager instead of less(1) if you prefer, e.g. more(1) or most(1). There are even tools that take plain text with ANSI color escapes and convert it into appropriately colorized PostScript, PDF, or HTML for web pages. So this would open many more possibilities. (Yes, I know there are already programs for syntax highlighting of code for web pages, but those don't work with joe's syntax files, so it would be difficult to get the same colors as inside joe.)
The more I think about it, the more use cases come to my mind. :-)