Hello, Pzz, you wrote: Pzz>> the programs compiled by it gcc, only in also it is possible to launch, let and built in in . Pzz> Venda with built in supports now two executable formats: native EXE, and native ELF. And so, I wanted to tell that gcc which there inside , produces on output ELF, instead of EXE. And I suppose that if you professionally write box under it does not approach you, to you is necessary EXE, enveloped in the installer. And I wanted to specify that compiled ELF will work in any , not only built in Windows. Pzz> I, by the way, do not believe that in this construction as someone expressed " a kernel executes system requests ". I suppose that they launched present a kernel, either in , or in a mode user mode linux, and accurately wore in user space necessary tracks between two worlds that launched thus the program looked more or less, as native. No, any kernel in Win, certainly, no. There is a difference in semantics of system calls, but their essence in any OS is very similar. Objects of synchronization, operation with storage, file input-output etc. Linuksovye are broadcast inside WSL in calls of services NT of a kernel. I personally transferred WSL from 10 to 2016 server where it is not present. All WSL is 1 driver and 1 service.