I just came across a great site with lots of papers related to performance monitoring and tuning for Linux:

http://www.ufsdump.org

One paper I especially liked:

Extreme Linux Performance Monitoring And Tuning

"The purpose of this document is to describe how to monitor Linux operating systems for performance.  This paper examines how to interpret common Linux performance tool output.  After collecting this output, the paper describes how to make conclusions about performance bottlenecks."

Lots of great info!

I am not a Mac user, but in case anyone is interested in knowing which version of Python ships with OS X Leopard, the answer is Python 2.5.

Keeping up to date with what's going on in Linux kernel development and what to expect in the future isn't always easy.  The Linux Kernel Mailing List has very high traffic and is very technical.

Luckily, the Linux Foundation has provided the Linux Weather Forecast, which provides a high level roadmap of what's going on in kernel development and where it's all going.

Pretty handy for people depending on future features as well as casual observers that want to keep up to date with major kernel development activities.

Operating Systems of visitors to my website and blog over the past 30 days.
(Results with less than 1% have been removed)

A report about scalability of virtualization techniques:

SCALABILITY COMPARISON OF 4 HOST VIRTUALIZATION TOOLS (QUETIER B / NERI V / CAPPELLO F)

"Virtualization tools are becoming popular in the context of Grid Computing because they allow running multiple operating systems on a single host and provide a confined execution environment.  In several Grid projects, virtualization tools are envisioned to run many virtual machines per host.  This immediately raises the issue of virtualization scalability."

4 types of virtualization tools are discussed in the context of scalability:

• Processor Virtualization
• Kernel Replication
• Operating System Virtualization
• Resource Virtualization

Sweet...
The history of entirely too many operating systems in way too high resolution.
... but great fun for OS geeks.

Operating System Genealogy:

• Unix Timeline
• Non Unix Timeline