As of 2015, Vectorworks is available in 64bit on both Mac and Windows. On the Mac side, Vectorworks 2015 (and later) will be 64bit only. On the Windows side, Vectorworks 2015 will have both 32bit and 64bit versions.
What does 64bit mean for the average user?
Full access to hardware resources:
Before becoming 64bit, Vectorworks 2014 and prior were only able to use ~3.5GB of RAM, or memory, regardless of how much you had installed. So even if you have 16GB of memory, Vectorworks 2014 would be capable of accessing 3.5GB, leaving the rest unused. Now, Vectorworks can access effectively as much memory as you are able to install on a given computer, however the average computer built at the time of this article will normally have a much lower memory limit around 16 or 32GB, determined by its hardware.
Vectorworks running as a 64bit application means it can handle large files without running into errors and reference more files at the same time. It is also able to handle much more complex files with high vertex or poly geometry counts without hitting the memory limit of previous versions. It will simply plow through and complete the operation where 32bit versions would have failed in the past.
How can I tell if I have a 64bit operating system?
For Windows users, see this article.
For Mac users, if you have OS X 10.8 or later, you are using a 64bit operating system. Most users running 10.7 are also 64bit as well but this can be confirmed here.
Can I still run the 32bit version if I want?
Yes, but there are no benefits in doing so.
Can I run the 64bit version of the application if I only have a 32bit operating system?
Unfortunately no. The system requirements for Vectorworks 2015 can be found here.
Can you tell me everything there is to know about 64bit computing?
This is the best place to start.
Edited by JimW