Comment 3 for bug 751027

From looking at the list of defaults, I personally see no need for Ask.com or eBay (and Yahoo + Bing, but we need to be fair to them!), and I agree that most people probably won't have any need for them either.

My view is that if AskUbuntu is to be an official help source, having it in there would be perfect for new users. As much exposure as possible :)

In regards to actually getting the search engine, it's defined by: http://askubuntu.com/opensearch.xml
Linked in the HTML with: <link rel="search" type="application/opensearchdescription+xml" title="Ask Ubuntu - Stack Exchange" href="/opensearch.xml">

Within my .mozilla config directory I have the file:

valorin@gandalf:~/.mozilla/firefox/6fnc78a6.default/searchplugins$ ls -la
total 28
drwxr-xr-x 2 valorin valorin 4096 2011-04-05 15:38 .
drwx------ 10 valorin valorin 12288 2011-04-05 20:37 ..
-rw-r--r-- 1 valorin valorin 2015 2011-04-05 15:38 ask-ubuntu.xml
valorin@gandalf:~/.mozilla/firefox/6fnc78a6.default/searchplugins$ cat ask-ubuntu.xml
<SearchPlugin xmlns="http://www.mozilla.org/2006/browser/search/" xmlns:os="http://a9.com/-/spec/opensearch/1.1/">
<os:ShortName>Ask Ubuntu</os:ShortName>
<os:Description>Search Ask Ubuntu: Q&amp;A for Ubuntu users and developers</os:Description>
<os:InputEncoding>UTF-8</os:InputEncoding>
<os:Image width="16" height="16">data:image/x-icon;base64,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</os:Image>
<os:Url type="text/html" method="GET" template="http://askubuntu.com/search?q={searchTerms}">
</os:Url>
</SearchPlugin>

So this would be the user-specific directory, the common system-wide one appears to be:

root@gandalf:/usr/lib/firefox-addons/searchplugins/en-GB# ls -la
total 32
drwxr-xr-x 2 root root 4096 2011-03-30 01:21 .
drwxr-xr-x 5 root root 4096 2011-03-31 09:17 ..
-rw-r--r-- 1 root root 1400 2011-03-26 02:52 amazondotcom.xml
-rw-r--r-- 1 root root 2252 2011-03-26 02:52 bing.xml
-rw-r--r-- 1 root root 1135 2011-03-26 02:52 eBay.xml
-rw-r--r-- 1 root root 2236 2011-03-26 02:52 google.xml
-rw-r--r-- 1 root root 1178 2011-03-26 02:52 wikipedia.xml
-rw-r--r-- 1 root root 1102 2011-03-26 02:52 yahoo.xml

I hope that gives you what you need.