vista is very bad
vista not running on 256MB of ram
XP barely ran on 256MB if you were using your computer for things more than email/document creation...
What people who throw the "Vista needs ridiculous resources" argument fail to realize is that in the 6 years since XP, hardware has gone leaps and bounds beyond the software. It's no more expensive to create a computer today with 2-4GB RAM then it was in 2001 to create one with 128MB RAM.
That being said, Leopard's requirements look somewhat similar to Vista's
OS X Leopard Minimum Requirements wrote:# A PowerPC G4 (800 MHz or faster)-based, PowerPC G5-based, or Intel-based Mac
# A DVD drive
# At least 512 MB RAM
# 7 GB of hard disk space – 12 GB if Xcode is also installed[
Windows Vista Minimum Requirements wrote:800 MHz Processor
512 MB RAM
DirectX 9 capable GPU - 128 MB RAM supports up to 2,756,000 total pixels (e.g. 1920 × 1200)
20GB HDD Capacity
15GB of HDD Free Space
To argue a point that I just know
is going to be brought up is why Vista takes up more space than OS X. There's several reasons here, with the main one being that Vista brings a ton of libraries with it, ranging from WDDM to the .NET framework.
It's called technological progression. Without higher requirements which can take advantage of the new hardware, we'd probably still be stuck in 1983 in terms of computing power...