First VyOS release was in December 2013.
VyOS uses so called semantic versioning for release version numbers that consists of three parts, <major>.<minor>.<patch>, where major increments on backwards-incompatible changes, minor increments on backwards-compatible changes, and patch increments on bugfixes.
Development branches are named after chemical elements sorted by atomic number. Branch name is included in the version spec, like "1.0.2 (hydrogen)".
VyOS active branches:
|Version||First release||Latest release||Status||Code name||Based on||Kernel||Notable changes|
|?||None||None||Current alpha||Beryllium||Lithium||Not set||Port to Debian Jessie. See Beryllium.|
|1.2||None||None||Current development||Lithium||Helium||Not set||In progress. Last release based on Debian Squeeze-LTS.|
2014 Oct 10
2015 Aug 17
|Current stable||Helium||Hydrogen||3.13.11|| L2TPv3, Dummy interfaces, QinQ, Event handler, IGMP proxy.
Experimental: DMVPN, VXLAN
2013 Dec 22
2014 Sep 26
|Old stable||Hydrogen||Daisy||3.3.8|| First release from Vyatta Core 6.6 fork. Command scripting,
task scheduler, web proxy LDAP authentication, numerous bug fixes.