I'd be willing to put in the time to dig it out and put it in for the sake of openacs.org. Now that a new 4-based openacs.org effort is seriously under way, I can't commit the time.
But if anybody working on an OACS 3.2.5-based site wants to implement it, it's really easy.
I managed to find an old ACS 3.x tar-ball, and in there you'll find:
packages/acs-core/text-html-procs.tcl
which contains all the procs.
Then all you need to do is add calls to ad_convert_to_html at various places in www/bboard/*.tcl:
confirm.tcl:[ad_convert_to_html -html_p $html_p -- $message]
fetch-msg.tcl:[ad_convert_to_html -html_p $html_p -- $message]
grep: graphics: Is a directory
post-reply-top.tcl:[ad_convert_to_html -html_p $html_p -- $message]
q-and-a-fetch-msg.tcl:append whole_page "[ad_convert_to_html -html_p $html_p -- $message]
q-and-a-fetch-msg.tcl: append this_response "[ad_convert_to_html -html_p $html_p " $message"]
grep: text: Is a directory
grep: unified: Is a directory
usgeospatial-fetch-msg.tcl:[ad_convert_to_html -html_p f $message]
I think that's it! If something doesn't work as expected, feel free to ask.