Good Shell Coding Practice
Things you ought to know when programming in Bash.

The Mono project or The dotnetfaq
Ximian's succesful effort to implement an Open Source alternative to C# and the .Net framework.

Vi IMproved tips
If you need a texteditor and you're an IT professional, look no further.

UI Design for Programmers or Free software and good UIs
Any programmer (even if they don't do UIs) should read this.