This is a good question. I usually have multiple PyCharm instances running and have never had a problem. I never thought about it until my wife started up PyCharm on my other computer and I got a notice saying another computer on the network was using a license and one of us needed to quit.<p>JetBrains needs to reassure us multiple instances are ok on same machine and across VMs. Will running the IDE in OS X and also a guest Linux VM look like multi-machine use? If so, that&#x27;s really a bad flaw in licensing.