Based on the existing snapshots and forum posts
2011.03.08- Dude v4.3 released - Dude v4beta3 released2015.12.03- Dude v4.3 download available - https://web.archive.org/web/20151203152206/https://mikrotik.com/thedude2015.12.04- Dude v6 first public test - The Dude is back! v6.34rc test build released2015.12.10- Dude v4.3 download not available - https://web.archive.org/web/20151210072106/https://mikrotik.com/thedude2016.01.29- Dude v6 released - v6.34 [current] is released!