Microsoft Vista has very high system requirements and poor hardware compatibility.
MacOSX / Chromium require their own particular hardware.
Webconverger can run on most PCs that meet Firefox's minimum requirements. In fact Webconverger does not require any hard drive (free disk space).
Webconverger can run well on recycled machines. Pentium 3s with 128MB of RAM are quite suitable PCs for Webconverger.
Webconverger does have issues with hardware that requires proprietary firmware, such as wireless network interfaces. See networking for advice.
In the future Webconverger aims to support other architectures and devices, besides the typical PC. Everything from TVs to mobile devices will converge to the Web. Please give some feedback if you have a particular device you want to see Webconverger on.