PHPDebugger is used for debugging PHP scripts.It can debug PHP scripts on local as well as remote servers. The Just In Time (JIT) gives the power to debug an entire web application through a Web Server.It has Inbuilt Profiler functionality.
Denwer is a collection of often-used web-servers for web-programmers. It is used to debug web-sites under Win32. Denwer includes: friendly installer; Apache; PHP; MySQL; Perl; virtual host management system; phpMyAdmin; sendmail stub; start/stop manager.