View source for Mork (file format)

{{lead too short|date=December 2011}}
{{Infobox file format
| name                   = Mork
| icon                   =
| logo                   =
| screenshot             =
| caption                =
| extension              = <code>.mab</code>, <code>.msf</code>, <code>.dat</code>
| mime                   =
| type code              =
| uniform type           =
| magic                  =
| owner                  = [[Netscape Communications Corporation|Netscape]], later [[Mozilla Foundation]]
| released               =
| latest release version =
| latest release date    =
| genre                  = [[Database]]
| container for          =
| contained by           =
| extended from          =
| extended to            =
| standard               = None ([[reference implementation]])
| url                    = [[devmo:Mork What Is It|Mozilla Developer Center]]
}}

'''Mork''' is a [[computer file format]] used by several [[email client]]s and [[web browser]]s produced by [[Netscape Communications Corporation|Netscape]] and [[Mozilla Foundation]]. It was developed by David McCusker<ref name=mccusker>{{cite web|url=https://developer.mozilla.org/en/Mork_What_Is_It |title=Mork What Is It&nbsp;— MDC |publisher=Developer.mozilla.org |archiveurl=https://web.archive.org/web/20191008061717/https://developer.mozilla.org/en-US/docs/Mozilla/Tech/Mork/What_is_it|archivedate=2019-10-08|date=2007-09-16 |accessdate=2009-08-19}}</ref> with the aim of creating a minimal [[database]] replacement that would be reliable, flexible, and efficient, and use a file format close to [[plain text]].<ref>{{cite web|url=https://developer.mozilla.org/en/Mork_Why |title=Mork Why&nbsp;— MDC |publisher=Developer.mozilla.org |date=2007-09-16 |accessdate=2009-08-19}}</ref>

The format was named after the character Mork from the TV show ''[[Mork & Mindy]]''.<ref name=mccusker/>
== Usage ==
The Mork format was used in most Mozilla-based projects, including the Mozilla browser suite, [[SeaMonkey]], [[Mozilla Firefox|Firefox]], and [[Mozilla Thunderbird|Thunderbird]]. In Firefox, it was used for browsing history data and form history data. In Thunderbird, it is still used for many things, such as address book data (.mab files) and the mail folder summaries (.msf files).
== Criticisms ==

Mork has many suboptimal properties. For example, despite the aim of efficiency, storing [[Unicode]] text takes three or six [[bytes]] per character.

The file format has been severely criticized by [[Jamie Zawinski]], a former [[Netscape Communications Corporation|Netscape]] engineer. He has criticized the apparent "textual" format on the grounds that it is "not human-readable",<ref>{{cite web|url=http://www.jwz.org/hacks/mork.pl |title=mork.pl: Perl program to extract metadata from a Mork database |first=Jamie | last = Zawinski |publisher= jwz.org |date= |accessdate=2009-08-19}}</ref> complaining that the impossibility of writing a correct [[parser]] for the format,<ref name="bugzilla">{{cite web|url=https://bugzilla.mozilla.org/show_bug.cgi?id=241438#c0 |title=Bug 241438&nbsp;– please make history.dat easier to parse (i.e., not Mork) |publisher=Bugzilla.mozilla.org |date= |accessdate=2009-08-19}}</ref> and referred to it as "...the single most braindamaged [sic] file format that I have ever seen in my nineteen year career".<ref name="bugzilla" />

In response, McCusker stated that the problems with Mork resulted from "conflicting requirements" and that he merely fixed scalability issues in bad code he "inherited".<ref>{{cite web | url = http://www.erys.org/resume/netscape/mork/jwz.html | archiveurl = https://web.archive.org/web/20050525080139/http://www.erys.org/resume/netscape/mork/jwz.html | archivedate = 2005-05-25 | title = erys: resume: netscape: mork: jwz | publisher = [[Internet Archive]] | date = 2005-05-25 | accessdate = 2009-08-19 | url-status = dead }}</ref>

''[[The Register]]'' lambasted the Mork database with their article "Why has Thunderbird turned into a turkey?"
<ref>{{cite web | url = https://www.theregister.co.uk/2010/08/08/thunderbird_3_no/ | title=Why has Thunderbird turned into a turkey?|publisher=www.theregister.co.uk}}</ref>

== Obsolescence ==
{{Update|section|date=December 2015}}
The replacement system, used for storing all user configuration data, is called [[MozStorage]]. MozStorage is based on the [[SQLite]] database. Beginning with Firefox 3.0, Firefox uses it for its history, form history and bookmark data. The storage engine was also included in Firefox 2.0, but only for use with extensions.<ref>{{cite web|last=Paul |first=Ryan |url=https://arstechnica.com/news.ars/post/20060430-6701.html |title=Features cut from Firefox 2 |publisher=Arstechnica.com |date=2006-04-30 |accessdate=2009-08-19}}</ref>

Mork was completely removed from Firefox in 2011.<ref>{{cite web|url=https://bugzilla.mozilla.org/show_bug.cgi?id=669040|title=Remove Mork from Mozilla-Central}}</ref><ref>{{cite web|url=http://blog.kylehuey.com/post/7168254347/mork-is-finally-gone|title=Mork to be removed from Firefox 7|work=Tumblr |last1=Huey |first1=Kyle }}</ref>

Plans existed for Mork to be replaced with MozStorage in Thunderbird 3.0.,<ref>{{cite web|url=https://wiki.mozilla.org/Thunderbird:Thunderbird3 |title=Thunderbird 3 Planning |publisher=Wiki.mozilla.org |date=2009-08-10 |accessdate=2009-08-19}}</ref> but as of 2025 still used the Mork file format.<ref>{{Cite web |title=11050 - Use mozStorage or IndexedDB instead of Mork for the message summary database |url=https://bugzilla.mozilla.org/show_bug.cgi?id=11050 |access-date=2025-04-06 |website=bugzilla.mozilla.org |language=en}}</ref> As of 2012, SeaMonkey used Mork for at least its POP and IMAP mail folders indexes.

== See also ==
* [[Berkeley DB]]

== References ==
{{Reflist}}

== External links ==
* [https://www-archive.mozilla.org/mailnews/arch/mork/primer.txt McCusker's description of the syntax]
* [https://www-archive.mozilla.org/mailnews/arch/mork/grammar.txt Grammar as mentioned in the above syntax description]
* {{cite web |url=https://developer.mozilla.org/en/Mork_Structure |title=Mork structure |url-status=dead |archive-url=https://web.archive.org/web/20210116025325/https://developer.mozilla.org/en-US/docs/Mozilla/Tech/Mork/Structure |archive-date=16 Jan 2021}}
* [https://wiki.mozilla.org/Mork Mozilla Wiki Mork page] (including links to tools for reading Mork documents)

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[[Category:Computer file formats]]
[[Category:Mozilla]]