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Shim (computing)
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<h2 id="examples">Examples</h2> <ul><li>Web <a href="/facts/Polyfill_(programming)/zn30XlHC">polyfills</a> implement newer <a href="/facts/Web_standard/3U9MLjD1">web standards</a> using older standards and <a href="/facts/JavaScript/XhhIIEsl">JavaScript</a>, if the newer standard is not available in a given <a href="/facts/Web_browser/2pfyymLs">web browser</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a></li> <li>Support of <a href="/facts/AppleTalk/6j3NRgTl">AppleTalk</a> on <a href="/facts/Apple_Macintosh/8GhnXTK0">Macintosh</a> computers, during the brief period in which <a href="/facts/Apple_Computer/oTJYta3k">Apple Computer</a> supported the <a href="/facts/Open_Transport/PvhNGVsV">Open Transport</a> networking system. Thousands of Mac programs were based on the AppleTalk protocol; to support these programs, AppleTalk was re-implemented as an OpenTransport "stack", and then re-implemented as an API shim on top of this new library.</li> <li>The <a href="/facts/Microsoft_Windows/bwhAhuSL">Microsoft Windows</a> Application Compatibility Toolkit (ACT) uses the term to mean <a href="/facts/Backward_compatibility/FbHFBu5y">backward compatible</a> libraries. Shims simulate the behavior of older versions of Windows for legacy applications that rely on incorrect or deprecated functionality, or correct the way in which poorly written applications call unchanged APIs, for example to fix <a href="/facts/Principle_of_least_privilege/sqsT4tln">least-privileged user account (LUA)</a> <a href="/facts/Software_bug/I1uSXySv">bugs</a>.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a></li> <li>bind.so is a shim library for <a href="/facts/Linux/9FvCKSTq">Linux</a> that allows any application, regardless of permissions, to bind to a listening socket or specify outgoing IP address.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> It uses the <a href="/facts/LD_PRELOAD/4vQ2J2xS">LD_PRELOAD</a> mechanism, which allows shims and other libraries to be loaded into any program.</li> <li>In the <i>type tunnel</i> pattern, a generic interface layer uses a family of shims to translate a heterogeneous set of types to a single primitive type used by an underlying API.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a></li></ul> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Adapter_pattern/jbLgy7ct">Adapter pattern</a></li> <li><a href="/facts/Application_virtualization/Wdgbbrun">Application virtualization</a></li> <li><a href="/facts/Driver_wrapper/M1XEW8eL">Driver wrapper</a></li> <li><a href="/facts/Glide_wrapper/J62MTkLJ">Glide wrapper</a></li> <li><a href="/facts/Glue_code/KUaEbYJK">Glue code</a></li> <li><a href="/facts/Stub_(computer_science)/oG08a8Ad">Stub (computer science)</a></li> <li><a href="/facts/Thunk_(compatibility_mapping)/2JFXex4w">Thunk (compatibility mapping)</a></li> <li><a href="/facts/Windows_on_Windows/n5pADD7l">Windows on Windows</a> (WoW)</li> <li><a href="/facts/Wrapper_function/nyy4XUdb">Wrapper function</a></li> <li><a href="/facts/Wrapper_library/b61otW6r">Wrapper library</a></li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="http://msdn.microsoft.com/en-us/library/windows/desktop/hh848039(v=vs.85).aspx">Microsoft Dev-Center - Windows 8 Client and Server 2012 application Compatibility</a></li> <li><a href="https://technet.microsoft.com/en-us/library/dd837644(v=WS.10).aspx">Microsoft TechNet - Understanding Shims</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"Your company's apps incompatible with Windows 7? Shim them, says Microsoft". Computerworld. 2009-03-21. Archived from the original on 2014-04-07. Retrieved 2014-04-05. <a href="https://web.archive.org/web/20140407082502/http://www.computerworld.com/s/article/9133382/Your_company_s_apps_incompatible_with_Windows_7_Shim_them_says_Microsoft%26displaylang%3Den" target="_blank">https://web.archive.org/web/20140407082502/http://www.computerworld.com/s/article/9133382/Your_company_s_apps_incompatible_with_Windows_7_Shim_them_says_Microsoft%26displaylang%3Den</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Demystifying Shims - or - Using the App Compat Toolkit to make your old stuff work with your new stuff". Microsoft TechNet. 2011-06-17. Retrieved 2014-04-05. <a href="http://blogs.technet.com/b/askperf/archive/2011/06/17/demystifying-shims-or-using-the-app-compat-toolkit-to-make-your-old-stuff-work-with-your-new-stuff.aspx&displaylang=en" target="_blank">http://blogs.technet.com/b/askperf/archive/2011/06/17/demystifying-shims-or-using-the-app-compat-toolkit-to-make-your-old-stuff-work-with-your-new-stuff.aspx&displaylang=en</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Axel Rauschmayer (2014). Speaking JavaScript. Shims Versus Polyfills. <a href="http://speakingjs.com/" target="_blank">http://speakingjs.com/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Axel Rauschmayer (2014). Speaking JavaScript. Shims Versus Polyfills. <a href="http://speakingjs.com/" target="_blank">http://speakingjs.com/</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"Microsoft Application Compatibility Toolkit 5.0". Microsoft. 2007-12-11. Retrieved 2008-06-24. <a href="http://www.microsoft.com/downloads/details.aspx?FamilyID=24da89e9-b581-47b0-b45e-492dd6da2971&displaylang=en" target="_blank">http://www.microsoft.com/downloads/details.aspx?FamilyID=24da89e9-b581-47b0-b45e-492dd6da2971&displaylang=en</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"Source code of bind.so". Daniel Ryde. 2010-01-09. Archived from the original on 2014-03-30. Retrieved 2014-04-05. <a href="https://web.archive.org/web/20140330151653/http://www.ryde.net/code/bind.c.txt" target="_blank">https://web.archive.org/web/20140330151653/http://www.ryde.net/code/bind.c.txt</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Wilson, Matthew (August 2003), "Generalized String Manipulation: Access Shims and Type Tunneling", C/C++ Users Journal, 21 (8) <a href="http://www.drdobbs.com/cpp/184401689" target="_blank">http://www.drdobbs.com/cpp/184401689</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> </ol>