This signed applet for IE4 browsers uses Microsoft J/Direct technology to provide direct access from Java to the Win32 kernel32.dll library function GlobalMemoryStatus() to dynamically display current RAM memory usage.
[This applet returns identical results to the Windows Task Manager/Performance
tab on Win2000 systems. On Win2000, standard install of IE5.1 uses ~ 7 Mb RAM, and the MS JVM uses an additional ~ 8 Mb RAM.]
References
Java source code
Windows Status Information from Windows API