There have been quite a few questions posed since the official announcement by Patrick Volkerding that Slackware is now releasing an official x86_64 port.
These questions normally stem about 32bit compatibility etc.
Here are a few answers that I hope will resolve any doubts/questions/concerns you may have, at least for now. These are of my own opinion and may not be completely factual.
1) Is Slackware64 multilib? (support both 64bit and 32bit programs)
A: Yes. It is multilib.
2) Does Slackware64 include the needed 32bit compatibility libraries necessary to run 32bit applications?
A: No, it does not include any 32bit compatibility libraries at this time.
3) Can I build 32bit applications on Slackware64?
A: From research and talking with other Slackware64 testers, it appears that gcc/glibc does NOT support building with -m32 flag for 32bit binary output. I have no idea if this is going to change in the future or not.
4) Is there any easy way to include the 32bit compatibility libraries?
A: The short answer is, possibly. Its been debated that you can use the c/ series from Slamd64-current in Slackware64 and gain the ability to run 32bit applications “out of the box.” However, I have not tested this and right now is more of a theory.
One other note, if you want to RUN 32bit applications without the compatibility libraries you will need to get a static built binary that includes those libraries. This in itself isn’t a bad solution per se, but it also means that you will be looking at VERY large binaries.
I hope this helps to answer some questions. If any of this is inaccurate or could use some clarification, please don’t hesitate to drop me a line and let me know.