Various people have integrated various different chat or instant
messaging tools into their OpenACS sites, including Jabber, IRC, and
NFC Chat. But AFAIK none of those have been rolled back into the
standard OpenACS distribution.
It's been discussed here in the past, here are 3 threads from
June 2003, and
Searching the forums will definitely find more.
The jabber package is rolled back in /contrib. Additionally it is currently under test in another site, once the test has proven successful the postgres version will be updated as well and the whole package will make it into the main distribution tree.
Nevertheless, the installation requirements are still not "automatic" as with other packages ...