I thought that some of the original onslaught maps didn't have enough variety in their link setups - or their link setups weren't good enough...
For a server to use them, I think it just has to put the ini files into the ut2004\system\ directory.
There are of course more possible link setups than this, but these are the ones I thought would be pretty fun to play.
http://www.users.on.net/~wenke/ut200...ONS-Tricky.ini

http://www.users.on.net/~wenke/ut200...Stronghold.ini

http://www.users.on.net/~wenke/ut200...-FrostBite.ini

http://www.users.on.net/~wenke/ut200...S-Primeval.ini

http://www.users.on.net/~wenke/ut200...ONS-Torlan.ini
For a server to use them, I think it just has to put the ini files into the ut2004\system\ directory.
There are of course more possible link setups than this, but these are the ones I thought would be pretty fun to play.
http://www.users.on.net/~wenke/ut200...ONS-Tricky.ini

http://www.users.on.net/~wenke/ut200...Stronghold.ini

http://www.users.on.net/~wenke/ut200...-FrostBite.ini

http://www.users.on.net/~wenke/ut200...S-Primeval.ini

http://www.users.on.net/~wenke/ut200...ONS-Torlan.ini
