compile & install Apache with mod_voc: 
There are two ways to do it: built-in module and DSO (shared module, which will be loaded by Apache if needed) 
Built-in module: 
configure apache, i.e.:
./configure --activate-module=/path/to/mod_voc.c 
compile it (make), install (make install)
Check that you have mod_voc.c in your httpd (httpd -l) 
DSO module:
Check that you have apache compiled with mod_so.c module (httpd -l)
Check that you have Apache-headers (i.e. on some Linuxes if you'd installed apache from .rpm, you need to install a package 'apache-devel')
run apxs -i -a -c mod_voc.c in the directory where mod_voc.c is placed (data/daemon)
-c will compile .so for you
-i will install module into apache's directory
-a will add 'LoadModule' directive into apache's config file
So combine flags as you need. 
compile the daemon with mod_voc support:
gmake MOD_VOC=1 
select the name for the unix-socket which will be used for forwarding of socket-info. For example, /tmp/vochat. If you have several chats, you need different names. 
configure apache. Into (Virtual)host-configblock, add something like 
<IfModule mod_voc.c>
	<Location /vocd> 
    SetHandler	voc-handler 
    VocSocket    /tmp/vochat 
	</Location>
</IfModule>
/vocd -- is the url (relative in this example) of the daemon, which you want to use 
/tmp/vochat -- is your unix-socket name (p.3) 
restart apache (check config with apachectl configtest and then restart with apachectl restart) 
configure chat, on step 2 of chat/admin/configure.php: 
Set Daemon LISTEN-type to mod_voc type. 
Set mod_voc socket to the value defined above (/tmp/vochat in our example). 
Set Daemon URL to Chat-URL/Vocd_Location, where Vocd_Location is the 'Location' value from Apache's config (/vocd in our example). 
start (or restart) the daemon. 
enjoy :)