If you think Planetside 1 is still going you are sorely joking. It probably doesn't even have 1k active players and its free to play, as a fan service.
Everquest 1 is almost in the same boat, doesn't mean anything.
Everquest 2 for example got demolished by WoW and every other MMO - It's a shell of its former self.
I guess you could call them alive, people on life support are technically alive as well - doesn't mean its a good game or "in good condition"
Age of Conan is my personal favourite, I don't even think they patch that game much anymore since they gambled on TSW.
http://www.ageofconan.com/news/monthly_development_update_may_2015
Their forum is still very active also from what I just checked.
So yeah.. they still patch it, still update it.
They are still going - you don't need to be top or have millions of members to be considered alive.
Even 1k active players is a lot tbh, more than enough... I know 3 friends IRL who play Planetside (independently, not together) so it's clearly still going, they are still getting a lot of enjoyment from it.