This tool has been hitting the news, including some mentions in the SANS ISC Diary.
It’s not actually a new attack (it’s been around since 2005) but this is the first time a packaged tool has been released for the attack.

Slowloris holds connections open by sending partial HTTP requests. It continues to send subsequent headers at [...]

The Web Security Gateway is a security-centric distribution of the Apache web server, bundled with additional security modules, and configured as a front-end (reverse) HTTP proxy. The goal is to mirror most of the features of commercial web application “firewalls”, with free and Open-Source software.
The Web Security Gateway provides a configurable caching, authentication, input validation, [...]

What Is Mod AntiTamper (AT)
AntiTamper is an Apache 2.x module that could be used to prevent some sort of url and cookie tampering.
Specifically, AT could stop a lot of those malicious bots that take advantage from search engines. Moreover, attack techniques like HTTP Response Splitting and session hijacking/fixation will be mitigated.

Is important to notice that [...]

Im a tinkerer. I can’t say I’m expert in anything more than ASP and MSSQL, but I make a point of playing and learning anything new and wanky. I’ve tweaked dBase, fiddled with Python, installed Apache, destroyed MS2003 server, plugged in SUN boxes, screamed at VisualStudio, urinated on Fedora, set fire too Game [...]