I’ve seen that Router OS could be OpenWRT based in this thread, and on Openwrt forum :
http://forum.mikrotik.com/t/confused-by-metarouter-applicability/38975/1
https://forum.openwrt.org/viewtopic.php?id=13547&p=2
Some guys are talking about Router OS GPL violation.
http://lists.gpl-violations.org/pipermail/legal/2008-February/001231.html
Can you clarify this ? Is router OS only Linux based, is it OpenWRT based, or is it fully proprietary ?