Mozilla firefox -
Mozilla Firefox is a Free and Open Source web browser developed by the Mozilla Foundation.
It can have many add-ons which give it extra capabilities.
Anonymous Browsing
Mozilla Firefox can be used in anonymous browsing (see The Onion Router. However, it is known that Firefox reveals computer's uptime in TLS (SSL) "Client Hello" packets allowing investigator correlate anonymous and non-anonymous traffic 1.
This bug affects Firefox 2 (all versions) and Firefox 3 Beta3.
History
Firefox 3 stores the history of visited sites in a file named places.sqlite. This file uses the SQLite database format.
places.sqlite can be found in the following locations:
On Linux
/home/$USER/.mozilla/firefox/$PROFILE.default/places.sqlite 
On MacOS-X
/Users/$USER/Library/Application Support/Firefox/Profiles/$PROFILE.default/places.sqlite 
On Windows XP
C:\Documents and Settings\%USERNAME%\Application Data\Mozilla\Firefox\Profiles\%PROFILE%.default\places.sqlite 
On Windows Vista, 7
C:\Users\%USERNAME%\AppData\Roaming\Mozilla\Firefox\Profiles\%PROFILE%.default\places.sqlite 
Timestamps
The places.sqlite uses the following timestamps.
The moz_historyvisits.visit_date is in (the number of) microseconds since January 1, 1970 UTC
Some Python code to do the conversion into human readable format:
date_string = datetime.datetime( 1970, 1, 1 ) + datetime.timedelta( microseconds=timestamp ) 
Example queries
Some example queries:
To get an overview of the visited sites:
SELECT datetime(moz_historyvisits.visit_date/1000000, 'unixepoch', 'localtime'), moz_places.url FROM moz_places, moz_historyvisits WHERE moz_places.id = moz_historyvisits.place_id; 
Downloads
Firefox 3 stores the history of downloads sites in a file named downloads.sqlite. This file uses the SQLite database format.
downloads.sqlite can be found in the same location as places.sqlite.
Note it looks that Firefox 21 (or earlier?) stores the downloads as part of the bookmarks in moz_bookmarks and moz_annos in places.sqlite
Timestamps
The places.sqlite uses the following timestamps.
The moz_downloads.startTime and moz_downloads.endTime are in (the number of) microseconds since January 1, 1970 UTC.
Example queries
Some example queries:
To get an overview of the downloaded files:
SELECT moz_downloads.startTime, moz_downloads.source, moz_downloads.currBytes, moz_downloads.maxBytes FROM moz_downloads; 
Disk Cache
The Mozilla Firefox disk cache uses the Firefox Disk Cache Format and can be found in:
Version 1
On Linux
/home/$USER/.mozilla/firefox/$PROFILE.default/Cache/ 
On MacOS-X
/Users/$USER/Library/Caches/Firefox/Profiles/$PROFILE.default/Cache/ 
On Windows XP
C:\Documents and Settings\%USERNAME%\Local Settings\Application Data\Mozilla\Firefox\Profiles\%PROFILE%.default\Cache\ 
On Windows Vista, 7
C:\Users\%USERNAME%\AppData\Local\Mozilla\Firefox\Profiles\%PROFILE%.default\Cache\ 
Version 2 - Firefox 32 and later
On Linux
/home/$USER/.mozilla/firefox/$PROFILE.default/cache2/ 
On MacOS-X
/Users/$USER/Library/Caches/Firefox/Profiles/$PROFILE.default/cache2/ 
On Windows XP
C:\Documents and Settings\%USERNAME%\Local Settings\Application Data\Mozilla\Firefox\Profiles\%PROFILE%.default\cache2\ 
On Windows Vista, 7
C:\Users\%USERNAME%\AppData\Local\Mozilla\Firefox\Profiles\%PROFILE%.default\cache2\ 
Settings
URL:
about:config 
See Also
Firefox Disk Cache Format
Mozilla Firefox History File Format
SQLite database format
External Links
Official website
Profile folder - Firefox
Firefox 3 – downloads.sqlite
Mozilla Firefox Releases