Sherlock, named after fictional detective Sherlock Holmes, was a file and web search tool created by Apple Inc. for the PowerPC-based "classic" Mac OS, introduced in 1998 with Mac OS 8.5 as an extension of the Mac OS Finder's file searching capabilities. Like its predecessor (System 7.5’s revamped 'Find File' app, adapted by Bill Monk from his 'Find Pro' find program[1]), Sherlock searched for local files and file contents on a Mac, using the same basic indexing code and search logic found in AppleSearch. Sherlock extended the system by enabling the user to search for items on the World Wide Web through a series of plug-ins, which employed existing web search engines. These plug-ins were written as plain text files, so that it was a simple task for a user to write a Sherlock plug-in.
Sherlock was replaced by Spotlight and Dashboard in 2005 with Mac OS X 10.4 Tiger, although Apple continued to include it with the default installation. Since most of the standard plug-ins for Sherlock provided by Apple itself no longer function, it was officially retired and removed in the release of Mac OS X 10.5 Leopard in 2007.
Data
The Sherlock 2 search plug-in was an SGML document, and was typically given the ".src" file extension. The Sherlock plug-in was composed of three parts, identified by their element names: <search>, <input>, and <interpret> tags. These elements allowed Sherlock to (respectively) identify a search engine's web page and the parts that are relevant to searching, as well as returning the results of the search. There was also a facility for defining how a Sherlock plug-in could update itself.
Sherlock search plug-ins could also be used (with minor modifications) in Mozilla's browser suites. These plug-ins were, appropriately enough, known as Mycroft project plug-ins (named after Mycroft Holmes, Sherlock Holmes' older brother). Among some of the changes made in the Sherlock file format were the separation of the automatic update element (which formed part of the <search> element) and the icon (provided in a separate file in Mozilla and part of the resource fork in Sherlock).
Sherlock 3 channels
The Sherlock 3 search plug-in was a web application, which was downloaded on the fly from a server to ensure the most current version. As information on the internet is subject to change so quickly, this was one way for Apple to guarantee the up-to-date version. A channel consisted of a web directory with an index. This usually pointed to a sub-directory (usually called "Channel") which contained the code XML, any Script XML, and localized lproj directories (nib file and Localized Text Resources as a plist).
Advocates of Watson made by Karelia Software, LLC claim that Apple copied their product without permission, compensation, or attribution in producing Sherlock 3.[citation needed] Some disagree with this claim, stating that Sherlock 3 was the natural evolution of Sherlock 2, and that Watson was obviously meant to have some relation to Sherlock by its very name.[citation needed]
Sherlocked as a term
The phenomenon of Apple releasing a feature that supplants or obviates third-party software is so well known that being Sherlocked has become an accepted term used within the Mac and iOS developer community.[2][3][4]
Sherlock was replaced by Spotlight in Mac OS X 10.4 Tiger for hard drive searches, and replaced by Dashboard for other functionality, but remained as a stand-alone program with its channels. It was completely removed in Mac OS X 10.5 Leopard.