Apache is the most popular webserver on the Internet, quite possibly the best in terms of security, functionality, efficiency, and speed. Changelog available here.
Changes: Fixed a Cross Site Scripting vulnerability in the default error page of Apache 2.0 before 2.0.43, and 1.3.x up to 1.3.26, when UseCanonicalName is "Off" and support for wildcard DNS is present which allows remote attackers to execute HTML and javascript as other web page visitors via the Host: header.