The current release of the Randomizer is 1.6.3b, released 26-06-2015.
There is no longer an alternative release as of 1.6.0 - the main release now uses the same system as the alternative did before.
Since there's no longer a download page with a changelog for each version, you can see the list of changes per version by clicking here.
Click here for a full listing of old versions.
If you're interested in the source code, you can browse that by clicking here.