wine architecture
winehq wiki: Architecture overview
windows 9x architecture
+---------------------+ \
| Windows EXE | } application
+---------------------+ /
+---------+ +---------+ \
| Windows | | Windows | \ application & system DLLs
| DLL | | DLL | /
+---------+ +---------+ /
+---------+ +---------+ \
| GDI32 | | USER32 | \
| DLL | | DLL | \
+---------+ +---------+ } core system DLLs
+---------------------+ /
| Kernel32 DLL | /
+---------------------+ /
+---------------------+ \
| Win9x kernel | } kernel space
+---------------------+ /
+---------------------+ \
| Windows low-level | \ drivers (kernel space)
| drivers | /
+---------------------+ /
windows NT architecture
+---------------------+ \
| Windows EXE | } application
+---------------------+ /
+---------+ +---------+ \
| Windows | | Windows | \ application & system DLLs
| DLL | | DLL | /
+---------+ +---------+ /
+---------+ +---------+ +-----------+ \
| GDI32 | | USER32 | | | \
| DLL | | DLL | | | \
+---------+ +---------+ | | \ core system DLLs
+---------------------+ | | / (on the left side)
| Kernel32 DLL | | Subsystem | /
| (Win32 subsystem) | |Posix, OS/2| /
+---------------------+ +-----------+ /
+---------------------------------------+
| NTDLL.DLL |
+---------------------------------------+
+---------------------------------------+ \
| NT kernel | } NT kernel (kernel space)
+---------------------------------------+ /
+---------------------------------------+ \
| Windows low-level drivers | } drivers (kernel space)
+---------------------------------------+ /
wine architecture
+---------------------+ \
| Windows EXE | } application
+---------------------+ /
+---------+ +---------+ \
| Windows | | Windows | \ application & system DLLs
| DLL | | DLL | /
+---------+ +---------+ /
+---------+ +---------+ +-----------+ +--------+ \
| GDI32 | | USER32 | | | | | \
| DLL | | DLL | | | | Wine | \
+---------+ +---------+ | | | Server | \ core system DLLs
+---------------------+ | | | | / (on the left side)
| Kernel32 DLL | | Subsystem | | NT-like| /
| (Win32 subsystem) | |Posix, OS/2| | Kernel | /
+---------------------+ +-----------+ | | /
| |
+---------------------------------------+ | |
| NTDLL | | |
+---------------------------------------+ +--------+
+---------------------------------------+ \
| Wine executable | } unix executable
+---------------------------------------+ /
+---------------------------------------------------+ \
| Wine drivers | } Wine specific DLLs
+---------------------------------------------------+ /
+------------+ +------------+ +--------------+ \
| libc | | libX11 | | other libs | } unix shared libraries
+------------+ +------------+ +--------------+ / (user space)
+---------------------------------------------------+ \
| Unix kernel (Linux,*BSD,Solaris,OS/X) | } (Unix) kernel space
+---------------------------------------------------+ /
+---------------------------------------------------+ \
| Unix device drivers | } Unix drivers (kernel space)
+---------------------------------------------------+ /
Wine must at least completely replace the Big Three DLLs (KERNEL/KERNEL32, GDI/GDI32, and USER/USER32), which all other DLLs are layered on top of. But since Wine is (for various reasons) leaning towards the NT way of implementing things, the NTDLL is another core DLL to be implemented in Wine, and many KERNEL32 and ADVAPI32 features will be implemented through the NTDLL.