The mozilla developer center has an article about new features for developers in Firefox 2.
Among others it covers how to create a custom search plugin.
I created such a plugin for a site I use frequently:
If you are interested in the code:
<?xml version="1.0"?>
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
<ShortName>www.stuttgart.de</ShortName>
<Description>Search www.stuttgart.de</Description>
<Image height="16" width="16" type="image/x-icon">data:image/x-icon,%00%00%01%00%01%00%10%10%00%00%01%00%08%00h%05%00%00%16%00%00%00(%00%00%00%10%00%00%00%20%00%00%00%01%00%08%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%01%00%00%00%00%00%00%F1%F1%F1%00uuu%00www%00%86%86%86%00%83%83%83%00%FA%FA%FA%00~~~%00%F7%F7%F7%00%7B%7B%7B%00%F5%F5%F5%00nnn%00%8A%8A%8A%00%CC%CC%CC%00%BB%BB%BB%00%EA%EA%EA%00rrr%00%DE%DE%DE%00zzz%00%D8%D8%D8%00%7C%7C%7C%00ppp%00%92%92%92%00%EE%EE%EE%00%F9%F9%F9%00%E6%E6%E6%00%87%87%87%00%EC%EC%EC%00%A1%A1%A1%00%B1%B1%B1%00%E4%E4%E4%00%D0%D0%D0%00%C3%C3%C3%00%FD%FD%FD%00%9B%9B%9B%00%E8%E8%E8%00%D9%D9%D9%00%E5%E5%E5%00%B5%B5%B5%00%FE%FE%FE%00%BC%BC%BC%00%C6%C6%C6%00%96%96%96%00%94%94%94%00%D7%D7%D7%00%81%81%81%00%C0%C0%C0%00%90%90%90%00%D3%D3%D3%00%DB%DB%DB%00%9C%9C%9C%00%F8%F8%F8%00%AD%AD%AD%00mmm%00%82%82%82%00%8D%8D%8D%00%84%84%84%00%95%95%95%00%8F%8F%8F%00lll%00%D4%D4%D4%00kkk%00%C7%C7%C7%00%8B%8B%8B%00%E1%E1%E1%00%D6%D6%D6%00%A8%A8%A8%00%D5%D5%D5%00%A5%A5%A5%00%CB%CB%CB%00%DD%DD%DD%00%EF%EF%EF%00%AC%AC%AC%00%CA%CA%CA%00%97%97%97%00yyy%00sss%00ttt%00vvv%00%7D%7D%7D%00%7F%7F%7F%00%80%80%80%00xxx%00%FF%FF%FF%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%03PPPPPOQN%0B%19NPPP%03NQQQQ%015%1C%06%25%1DJMQQNOQQQQM%06%220N%403%14QQOOQQQQQM%11%0CC%1B%0EOMQOOQQLMQQ%3A%1CR%07BJ%02QOOQK%04O%01%0A%04%0ERR%0D4KQOO%0F%15%1A*KG%18RRR%05%2F1LOOLD%00(%24RRRRRFR%07P%11%19%3F%23%00RRRRR%1A%3D%3E%00R%0D%08%06%2B%12%16%26RRR'%02%3C%15RR%17%0B%08%04%09%0C%3BR%20%05%187K%13H%10%12APK6N)%1DR2%17-L%01LJN9OJ%0A8%00%16R%05%09%1FKQ%02MM%13OQL.ERRR%07%1B%0FQQQQONQJL%14I%10%1E!%01%02QQQQN%03PPPPQ%2C%08JPPPPPP%03%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00%00</Image>
<Url type="text/html" method="GET" template="http://www.stuttgart.de/sde/search.php?action=search&search={searchTerms}"/>
<InputEncoding>iso-8859-15</InputEncoding>
<AdultContent>false</AdultContent>
</OpenSearchDescription>
To use this search plugin copy the above code in a file called sde.xml and save it into the searchplugin folder of your Firefox installation, which is normally: C:\Program Files\Mozilla Firefox\searchplugins\
MrGierers World 