yserver:
    BIG-REQUESTS
    Composite
    DAMAGE
    DRI3
    GLX
    Generic Event Extension
    MIT-SCREEN-SAVER
    MIT-SHM
    Present
    RANDR
    RECORD
    RENDER
    SHAPE
    SYNC
    X-Resource
    XC-MISC
    XFIXES
    XFree86-VidModeExtension
    XINERAMA
    XInputExtension
    XKEYBOARD
    XTEST

Xwayland:
    BIG-REQUESTS
    Composite
    DAMAGE
    DOUBLE-BUFFER
    DRI3
    GLX
    Generic Event Extension
    MIT-SHM
    Present
    RANDR
    RECORD
    RENDER
    SECURITY
    SHAPE
    SYNC
    X-Resource
    XC-MISC
    XFIXES
    XFree86-VidModeExtension
    XINERAMA
    XInputExtension
    XKEYBOARD
    XTEST
    XVideo
    XWAYLAND

## GLX Extensions

### GLX_OML_sync_control

Mesa implements `glXGetMscRateOML()` on the client side by reading the current
mode through `XFree86-VidModeExtension`. Yserver implements Xorg's read surface
with the correct legacy/v2 wire layouts and the selected output's real
DRM/RANDR timing, monitor identity, programmable clock capability, viewport and
gamma ramp. This lets Mesa and ANGLE-based Flatpak clients derive the display
MSC rate while other VidMode readers see data consistent with RANDR instead of
unexpected `BadRequest` errors.

VidMode remains deliberately read-only because RANDR owns display
configuration. `GetPermissions` advertises only `XF86VM_READ_PERMISSION`, and
known mode/gamma writes fail with VidMode's `ClientNotLocal` error — the same
coherent fallback branch Xorg exposes to a client without write permission.
Yserver clients are physically local Unix-socket peers, so this is an explicit
server policy rather than a claim that they are remote.

### GLX_EXT_texture_from_pixmap

Implemented and tested on AMD, intel, Asahi and Qualcomm. It can NOT (read: NEVER) work on nvidia proprietary driver, and on
the only nvidia card I have (GTX 1050), the nouveau driver can not even bring up Xorg. Nouveau may work on other
cards, but untested.

## XDMCP (not an X11 extension)

XDMCP is a separate protocol over UDP, not an X11 extension, so it is not in
the lists above. Support (`-query`, `-indirect`, `-broadcast`) is an optional,
off-by-default Cargo build feature; see the "Optional build features" and
"XDMCP" sections of `docs/setup.md` and `yserver(1)`. Stage-2 ACL, IPv6 and
XDM-AUTHENTICATION-1 are not implemented.