I have been using Sony CD Architect for years but, it is not 64 bit and, it's no longer available What does everyone use nowadays to edit and create professional, Redbook standard CDs?

Samplitude is excellent for this purpose... as is Wavelab.

Check out a lighter version of Samplitude.  I believe they can all burn RedBook audio.
At this point (with CDs slowly going away), you probably don't want to spend $500 to burn audio CDs.

If you have Studio One Professional (or thinking about getting it), it includes some fantastic Layout, Mastering, Burning features.

↑↑↑↑↑ this or
https://hofa-plugins.de/e...ns/cd-burn-ddp-master/

I use a generic CD-burning application called Nero. I have CDA, but don't use it. Not because it's 32-bit, which shouldn't make any difference, but just because it's clunkier to use than Nero.

Thanks everyone for the great suggestions!
Since I am so accustomed to CD Architect, I would just stick with it but.... I am setting up a new computer and, I cannot find my CD Architect installer disc!! How could I lose that??!!! I don't know if I can copy it off my old computer to the new one, without the disc, or not. I doubt it.
Yes, I do have Studio One. I have never used the CD burning features in it before. Is it good?
Yeah, I know CDs are becoming less favorable but, here where I am, a master CD of a client's album project is still the preferred method of delivery. I'm sure, at some point, they will just stop making CDs or make them too expensive to be a viable option.

If you're making RedBook CDs for clients, you're most likely going to want more advanced layout features (crossfades/etc) than you'd find in a more "general-purpose" burning app like Nero, IMG Burn, etc.
 
Since you have Studio One, I'd highly recommend checking out its layout and burning features.
It's got everything you need to layout and create audio CDs (mastering features, advanced metering, DDP Export if your client is going to have professional CDs made, etc)

rodreb
I am setting up a new computer and, I cannot find my CD Architect installer disc!! How could I lose that??!!! I don't know if I can copy it off my old computer to the new one, without the disc, or not. I doubt it.

 
You can still access and download your CDA software (if you've registered it) at https://www.sonycreativesoftware.com/myaccount/home (if an older version) or https://www.magix.com/us/support/my-service-center/ if you've registered there since the transition. 

I have Nero 12, and use it less and less, will never upgrade it. I've found that Windows Media Player (v12) does everything I need to do for burning these days, for the few CDs I need to burn. Of course, it has nothing advanced, if you really need those extra features. I just set up the CD project as a Playlist, and burn from there. Most of my mastering is done within the DAW.
 
And what's so special about "Redbook standard CDs" . . . almost every generic burning software does that doesn't it ?