LiibreCAD 2 vs LiibreCAD 3

I see there are 2 versions, LibreCAD 2 and LibreCAD 3:

Mine is this from the About dialog:

LibreCAD
Version: master
SCM Revision: 2.0.9
Compiler: GNU GCC 5.3.1
Qt Version: 5.5.1
Compiled on: Mar 24 2016
...  ...

There is no version number on mine, installed in Linux Mint 18.
What version is it?

What is the difference between version LiibreCAD 2 and LiibreCAD 3?

If my version is LiibreCAD 2, where do I download LiibreCAD 3?

LibreCAD 3 is a completely new program,
and has not had an official release yet.

You're using 2.0.9,
and 2.1.1 is the latest version.

2.0.9 seems to be the latest release for
debian / ubuntu / mint.

https://forums.linuxmint.com/viewtopic.php?f=47&t=31954

We had someone maintaining a ppa,
but it's been inactive for a while.
https://launchpad.net/~librecad-dev/+archive/ubuntu/librecad-daily

You could try building from source.
https://github.com/LibreCAD/LibreCAD/wiki/Build-from-source

If anyone wants to start / maintain a new ppa,
that would be helpful.