I just checked on Davka’s site. It seems that they make Davkawriter7 in a Mac version, but not 6.
This is from their FAQ section:
How do I run DavkaWriter 6 on my Mac?
Posted on February 16, 2011 by Davka Tech Support
DavkaWriter is, essentially, a Windows program. There is no Mac version.
If you use Windows on your Mac, as many Mac users do, or if you use Windows emulation or virtualization, you can run DavkaWriter in that configuration.
Some alternatives for this are:
Those all require the user to have a copy of Windows XP, Vista, or 7. These alternatives provide full DavkaWriter functionality.