OS/2

#define INCL_DOSFILEMGR
#include <os2.h>
#define HF_STDOUT               /* Standard output handle */

static UCHAR szHelloWorld[] = "Hello Warped World!";

void main()
{
    ULONG cbWritten;

    while (1)
        DosWrite(HF_STDOUT,              /* Standard output handle */
                 szHelloWorld,           /* buffer to write        */
                 sizeof(szHelloWorld),   /* length of buffer       */
                 &cbWritten);            /* count of bytes written */
}