Interesting. I am using OS X 10.5.8 with only 2G memory and when programming with Python, PHP, gcc and Apache this is actually OK. Not brilliant, but not slow either. The machine tends to be on all day. I have noticed that Linux does seem to page more than it used to in recent years, this varies with the kernel. There is more Linux disk activity these days than in previous versions, regardless of what swappiness I tell it to use.
I use nano or vim as my editor mainly. The setup I use on Linux is much the same. I don't notice much of a difference in terms of performance between OS X or Linux for the text-based and command-line related stuff that I do. I could sit down and be happy in either OS X or Linux and it wouldn't matter to me which one I'm using. I also use mutt for my email and cmus for playing music in both environments so I am seldom out of the command line for anything.
Although I do find apt-get much more efficient and I can get packages faster and with less fuss with Linux.
I do also use brew on OS X.
As far as I'm concerned, for what I do, there isn't a lot of difference ... I hardly ever use XCode, though.
It's because you're using 10.5, last of the great OS-X's. Performance requirements went up in 10.6 and WAY up in 10.7. I have an old MBPro running 10.5 and it consistently feels faster (and is provably far more stable) than my new model work machine running 10.7
Really? Glad in many ways I am still using 10.5 then. I've no problem with stability. As you mention it seems quite rock solid.
I had no idea that the memory requirement for 10.6 or 10.7 was so high (I've heard anecdotal comments from non-tech friends). But then I'd also heard the official Apple line that 10.6 was meant to be better at memory management and slightly faster than 10.5 because the binaries were no longer dual PPC and Intel -- just Intel.
So, in God's name, why are the later versions so resource hungry?
10.6 switched the architecture from i386 to x86-64. Since many third party applications were still i386 binaries at the time of its release, both versions of every system library had to be loaded. That did increase memory use in some ways, but it's not really a problem anymore unless you use Word 2008.
But that's about it; 10.6 is much faster and more stable in every other way, that being the entire point of the release.
Of course, I should say 'was', since it's not even the current version. Unless you're posting from a time warp.
I use nano or vim as my editor mainly. The setup I use on Linux is much the same. I don't notice much of a difference in terms of performance between OS X or Linux for the text-based and command-line related stuff that I do. I could sit down and be happy in either OS X or Linux and it wouldn't matter to me which one I'm using. I also use mutt for my email and cmus for playing music in both environments so I am seldom out of the command line for anything.
Although I do find apt-get much more efficient and I can get packages faster and with less fuss with Linux.
I do also use brew on OS X.
As far as I'm concerned, for what I do, there isn't a lot of difference ... I hardly ever use XCode, though.