How The Kernel Manages Your Memory : Gustavo Duarte
http://duartes.org/gustavo/blog/post/how-the-kernel-manages-your-memory
Moserware: How .NET Regular Expressions Really Work
http://www.moserware.com/2009/03/how-net-regular-expressions-really-work.html
http://ghettochip.com/merb_internals
http://ghettochip.com/merb_internals

Knowing how tools you use work under the covers is a huge win for every developer out there and Merb is small and clean enough for everyone to understand it in a short period of time. You can learn a lot about HTTP, web frameworks design and even hidden gems of Ruby web servers (how many of you know that Thin can actually serve requests in threads and not block the event loop?).

ponder

good explanation of Ruby's threads & stack implementation

6s

ruby 1.8 mri assembly threads