'LTS' means Long Term Support

feren OS is based on Linux Mint which is based off of LTS releases of Ubuntu which are usually known to be in the form of this: 'XX.04 LTS' and the first release, 2015 is based on Ubuntu 14.04 LTS meaning you get the longest support of Ubuntu Releases and we always want to keep it that way. Even though it might be LTS, as more releases come, more programs will only support later versions of Ubuntu meaning you may have to Upgrade earlier than expected.