I had a hard time getting this applet to work with Internet Explorer, it would just show a grey box and lie "Class blah not found".
First I found out that I had to make an AWT applet instead of a JFC JApplet. Then I discovered that I had to download an officially discontinued version of the Java SDK (1.1.8) to get the applet to run on Microsofts VM (which is supposed to be 'modern'). I compiled it using TextPad.
Update: Now compiled with Blackdown Java 1.3.1, since I switched to GNU/Linux
Source code: TempConv.java
This applet has been developed by Andreas van Cranenburgh and David van Marlen.
Copyleft 2002 - All rights reversed