Documentation Source Text

<title>SQLite: Most Widely Deployed SQL Database</title>

<h2>Most Widely Deployed SQL Database</h2>

<p>We <em>believe</em> that there are more copies of SQLite
in use around the world than any other SQL database engine,
and possibly all other SQL database engines combined.  We cannot
be certain of this since we have no way of measuring either
the number of SQLite deployments nor the number of deployments
of other databases.  But we believe the claim is defensible.</p>

<p>The belief that SQLite is the most widely deployed SQL
database engine stems from its use as an embedded database.
Other database engines, such as MySQL, PostgreSQL, or Oracle,
are typically found one to a server.  And usually a single
server can serve multiple users.  With SQLite, on the other
hand, a single user will typically have exclusive use of

SQL database engines other than SQLite.  Not every website
runs an SQL database engine, and not ever SQL database engine
runs a website.  Larger websites run multiple
database engines.  But the vast majority of smaller websites
(the long tail) share
a database engine with several other websites,
if they use database engine at all.
And many large SQL database installations have nothing to do with
websites.
So using the number of websites as a surrogate for the number of operational
SQL database engines is a crude approximation, but it is the best
we have so we will go with it.  (Readers are encouraged to submit
better estimates.)</p>

<p>Now let's consider where SQLite is used:</p>

<a href="http://skypejournal.com/blog/archives/2006/04/how_many_users_does_skype_have_today.php">&#91;4]</a>.  All recent versions of the Skype
client use SQLite internally.</li>
<li>20 million Symbian smartphones shipped in Q3 2007
<a href="http://www.symbian.com/news/pr/2007/pr20079552.html">&#91;5]</a>
Newer versions of the SymbianOS have SQLite built in.  It is unclear
exactly how many Symbian phones actually contain SQLite, so we will
use a single quarter's sales as a lower bound.</li>
<li>10 million AOL subscribers use SQLite in the AOL email client that
comes bundled with their subscription.</li>
<li>10 million Solaris 10 installations, all of which require SQLite in
order to boot.</li>
<li>Millions and millions of copies of
<a href="http://www.mcafee.com/">McAfee</a> anti-virus software all
use SQLite internally.</li>
<li>Millions of iPhones use SQLite</li>
<li>Millions and millions of other cellphones from 
manufactures other than Symbian and Apple use SQLite.
This has not been publicly acknowledged by the manufactures
but it is known to the SQLite developers.</li>
<li>There are perhaps millions of additional deployments of
SQLite that the SQLite developers do not know about.</li>
</ul>

<p>