Can Xojo executables support declares from other programs?

I’m wondering if declares can be made from other languages to call executables made with Xojo?
If not, what’s the fastest alternative - stdin / stdout ?

you mean like Xojo declares ?
no
Xojo doesnt produce shared libraries that expose entry points like we use declares to access

you’d need some other mechanism depending on what it is the other app expects to do
a command line would work for certain things

Thanks Norman. Does anyone know the performance characteristics of Command line v using a socket to the executable, assuming the computers network subsystem is not very busy and the executable isn’t very big?

command lines and pipes do have their limits
UDP sockets or TCP Sockets can be fast - generally “fast enough” unless you’re really trying to shove a LOT of data as fast as possible (i/e distributed image processing is a good example and there are people doing this)
For that there are plugins that make it possible to use shared memory which is quite literally two apps collaborating and cooperating to share a segment of memory - things dont get faster than that

I have considered MonkeyBread shared memory but don’t know how it could be accessed by other languages… leading to my original question.

as far as I know mbs exposes the system level shared memory facilities

like this https://www.man7.org/linux/man-pages/man3/shm_open.3.html

Thanks Norman, that was helpful to know.

For MacOS, AppleEvents are also a great way to deal with the problem.