Editing Wine (software) (section)

=== Basic architecture ===

The programming interface of Microsoft Windows consists largely of [[dynamic-link library|dynamic-link libraries]] (DLLs). These contain a huge number of wrapper sub-routines for the system calls of the kernel, the NTOS kernel-mode program (ntoskrnl.exe). A typical Windows program calls some Windows DLLs, which in turn calls user-mode gdi/user32 libraries, which in turn uses the kernel32.dll (win32 subsystem) responsible for dealing with the kernel through system calls. The system-call layer is considered private to Microsoft programmers as documentation is not publicly available, and published interfaces all rely on subsystems running on top of the kernel. Besides these, there are a number of programming interfaces implemented as services that run as separate processes. Applications communicate with user-mode services through RPCs.<ref name="archi">{{cite web |title=Wine Developer's Guide/Architecture Overview |url=https://wiki.winehq.org/Wine_Developer%27s_Guide/Architecture_Overview#Wine_Overview |website=WineHQ |access-date=22 April 2019 |archive-date=22 April 2019 |archive-url=https://web.archive.org/web/20190422232117/https://wiki.winehq.org/Wine_Developer%27s_Guide/Architecture_Overview#Wine_Overview |url-status=live }}</ref>

Wine implements the Windows [[application binary interface]] (ABI) entirely in [[user space]], rather than as a [[Loadable kernel module|kernel module]]. Wine mostly mirrors the hierarchy, with services normally provided by the kernel in Windows<ref>See the "[[Windows service]]" article</ref> instead provided by a [[daemon (computing)|daemon]] known as the wineserver, whose task is to implement basic Windows functionality, as well as integration with the [[X Window System]], and translation of [[Signal (IPC)|signals]] into native Windows exceptions. Although wineserver implements some aspects of the [[Architecture of Windows NT|Windows kernel]], it is not possible to use native Windows drivers with it, due to Wine's underlying architecture.<ref name="archi"/>