Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
TreeSize - TreeSize tells you where precious disk space has gone to.
LiteSpeed Web Server - LiteSpeed Web Server (LSWS) is a high-performance Apache drop-in replacement.
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.