So this is just an quick post for finding out the VMWare ESX version you are running.
First connect to any one of your ESX servers. You can use any SSH utility but I like Putty. You can download it here http://www.chiark.greenend.org.uk/~sgtatham/putty/
Once logged into the ESX box. you can run the command
vmware –v
This will give you the output like 
As you can see, we are not doing a good job keeping up….