JavaScript
Regular Expressions in JavaScript don't support the single-line mode
Today, while working on a gadget involving some client-side development I have discovered that JavaScript doesn't support the single-line mode for Regular Expressions (Regex). Now why is that bad?
Minify your JavaScript - and save the KB's for later (Imtech JavaScript Minificator - Free Tool)
Recently I have spent quite some time measuring and tuning the performance of the Imtech SharePoint Enhancement Toolkit: a toolkit that I have built in order to achieve standards compliancy, accessibility and slightly more performance of SharePoint Web Content Management (WCM) solutions.