As the previous posts say OWB was once free to download.
Now it is bundled with CA PPM.
At one point CA outsourced the developent to ITDesign a major Clarity partner.
Some time later (2014) the think was reputedly be that if CA is responsible for OWB then CA should do the development as well.
At that time OWB betas could still be downloaded from ITDesign.
Then some time later it appears that the version that can be downloaded ITDesign site does not say beta and is fairly recent. That could indicate that development it back with ITDesign.
I have not seen any official statement about that.
As far as I see the latest version available outside CA PPM is at ITDesign site. Use that, you cannot get any other new version. Recently the changes have not been earthquaking so a minor difference in functionality and GUI does not matter that much if you just want to share plans with others.