Side-by-side assembly
lastmod 2022-03-14created 2022-03-141 edits
Side-by-side assembly (SxS, WinSxS) is a Microsoft Windows technology and a standard for executable files in Windows 98, Windows 2000, and later versions of Windows that attempts to mitigate problems that arise from the use of dynamic-link libraries (DLLs) in Microsoft Windows (collectively known as DLL hell). These problems include conflicts, missing DLLs, duplicate DLLs, and invalid or missing registration. With side-by-side, Windows stores multiple versions of a DLL in the WinSxS subdirectory of the Windows directory and loads them on demand. This reduces dependency problems for applications that include a side-by-side manifest.
Visual C++ 2005 and 2008 include all C runtime libraries in SxS. In Visual C++ 2010, however, the libraries no longer use this technology. Instead, the DLL's version number is included in the file name, which now means that different versions of a DLL are technically entirely different DLLs.