Iron for Mac OSX 10.5 or 10.6

[pat]

I consider OSX beyond 10.6.5 to be unsafe and intend never to install any later. Now I use 10.5.8.
I would like very much to use Iron. Are there prior versions that will work on Ma10.5.8 or 10.6.5?
If not I think it's important to produce them. Thank you for your service in making Iron.