Windows XP build.

Is it possible to add it? If not, why not?

Скорее всего это возможно, но MSDN запутал меня в данном вопросе.
На SP2 и выше сборка выглядит вполне возможной!

Should be possible, but there may be differences between different SP! Compilation looks easy, there are very few imports, and the build tools are quite classic.

#include <strings.h>

#ifdef _WIN32
    #include <winsock2.h>
#else
    #include <arpa/inet.h>
#endif

Version 2.1 of Winsock was supplied in an add-on package for Windows 95. It was an integral component of Windows 98, Windows NT 4.0, and all subsequent Windows releases. (Microsoft did not supply implementations of Winsock 2 for Windows 3.x or Windows NT 3.x.)
Recent versions of Winsock 2.x have been delivered with new Windows releases or as part of service packs.

Hello.
If anyone knows how to compile, please compile the exe file for windows xp x86 without SSE2 instructions. I will be very grateful. Or maybe there are some analogues for this operating system?

Is it possible to add it? If not, why not?

byedpi/conev.h

Line 13 in fdb91ec

#define poll(fds, cnt, to) WSAPoll(fds, cnt, to)

The WSAPoll function is defined on Windows Vista and later.

As a workaroud, it is possible to compile and run byedpi on Cygwin installed on WIndows XP.

install Cygwin 2.5.2 on XP as described on cygwin.com:
setup-x86.exe --no-verify --allow-unsupported-windows --site http://ctm.crouchingtigerhiddenfruitbat.org/pub/cygwin/circa/2016/08/30/104223
compile from source with GCC from Cygwin or get pre-compiled using GH Actions byedpi-x86-cygwin.zip and copy ciadpi.exe to C:\cygwin\bin.

Now you can run ciadpi from Cygwin bash shell.

Screenshot

As a workaroud, it is possible to compile and run byedpi on Cygwin installed on WIndows XP.

Thanks for the build. There is a remark, parameters: timeout, fake, ttl, tls-sni do not work.

ciadpi from Cygwin bash shell.

ciadpi --fake -1 --ttl 8
ciadpi: unknow option --fake
Please fix it