A neat tool to scan you apache server for “some” (more than 3.000) known security problems including general configuration problems (directory indexing) and wide spread scripts vulnerabilities.
Remember to verify each problem reported though!
Visit the Homepage for further information.
I recently found a great article on mysql performance blog giving you a short and precise description of what to tune in the first place.
This is a must!
After migrating from wordpress 2.1 to wordpress-mu 1.0 I was not able to write source code like XML inside <code> tags. I searched the web and tried some plugins - to no avail 
Finally I decided to go the brute force way by editing wp-includes/kses.php and removing the whole code. Therefor I changed the wp_kses method to:
# Don’t do anything
# just return the string untouched
return $string;
}
It is really ugly though…
Using CDATA to embed raw data within XML is a quite convinient feature. But the XML spec lacks the possibility to have a CDATA containing another CDATA or even the string ]]>.
So what happens if you put content like this within a CDATA section?
Your XML writer or at least any descent parser will complain it is not valid XML! Even the color coding on this page reveals that 
What to do?
The easiest (and IMHO most compatible) way of handling this is to build multiple CDATA sections, like this:
I guess almost everybody has been hit by the “IE shows only a blank page” issue while experimenting with XHTML back then. It is because IE requires a closing tag. The following fragment will not work in IE:
But this works:
Ok, we learned that.
Today I had a hard time with IE showing a white page and all I had done was converting an old .jsp into a .jspx file.
What happened?
After hitting google with every type of phrase I could imagine describing my problem, I finally found it out: The servlet container (Tomcat 5.5.12) removed the closing script tag because the content of the script tag was empty. DOH!
What did the trick?
For now I do the following:
Wow. If you love surprises - do web development.