Can you have 2 WoW clients open?

Can you please clarify for me if it's possible to have two separate World of Warcraft (WoW) clients open and running simultaneously on the same computer? I'm curious if this could be done for multi-tasking purposes, such as managing two different accounts or perhaps testing strategies in-game. Additionally, if it is feasible, are there any potential drawbacks or limitations to having multiple WoW clients open at the same time? Your insight would be greatly appreciated.