I've been using VirtualBox, and GNS3 for a while and recently I found out about Cisco Packet Tracer.

https://en.wikipedia.org/wiki/Packet_Tracer

I've downloaded it and it seems like this tool is focusing more into Cisco Networking.

The good things about this tool is I can run a lot of guests (pcs, routers, switches) and memory utilization is still very low. Not like GNS3 & VirtualBox.

My question is, can I run actual Linux OS in this packet tracer as I can run it on VirtualBox and GNS3?