diff --git a/src/c/file.d b/src/c/file.d
index 179d3e9d8..be970229e 100644
--- a/src/c/file.d
+++ b/src/c/file.d
@@ -1864,6 +1864,39 @@ cl_interactive_stream_p(cl_object strm)
 	@(return output)
 }
 
+cl_object
+ecl_make_stream_from_fd(cl_object fname, int fd, enum ecl_smmode smm)
+{
+   cl_object stream;
+   char *mode;			/* file open mode */
+   FILE *fp;			/* file pointer */
+
+   switch(smm) {
+    case smm_input:
+      mode = "r";
+      break;
+    case smm_output:
+      mode = "w";
+      break;
+    default:
+      FEerror("make_stream: wrong mode", 0);
+   }
+   fp = fdopen(fd, mode);
+
+   stream = cl_alloc_object(t_stream);
+   stream->stream.mode = (short)smm;
+   stream->stream.file = fp;
+   stream->stream.object0 = @'base-char';
+   stream->stream.object1 = fname; /* not really used */
+   stream->stream.int0 = stream->stream.int1 = 0;
+#if !defined(GBC_BOEHM)
+   fp->_IO_buf_base = NULL; /* BASEFF */; 
+   setbuf(fp, stream->stream.buffer = cl_alloc_atomic(BUFSIZ)); 
+#endif
+   return(stream);
+}
+
+
 void
 init_file(void)
 {
diff --git a/src/c/symbols_list.h b/src/c/symbols_list.h
index 49726592e..5d5ac137e 100644
--- a/src/c/symbols_list.h
+++ b/src/c/symbols_list.h
@@ -1454,6 +1454,8 @@ cl_symbols[] = {
 {MP_ "WITHOUT-INTERRUPTS", MP_CONSTANT, NULL, -1, OBJNULL},
 #endif
 
+{EXT_ "RUN-PROGRAM", SI_ORDINARY, si_run_program, -1, OBJNULL},
+
 /* Tag for end of list */
 {NULL, CL_ORDINARY, NULL, -1, OBJNULL}};
 
diff --git a/src/c/tcp.d b/src/c/tcp.d
index 2401bc8e9..0f255fa79 100644
--- a/src/c/tcp.d
+++ b/src/c/tcp.d
@@ -182,42 +182,6 @@ create_server_port(int port)
   return(conn);
 }
 
-/***********************************************************************
- * Interface from file descriptors to streams
- **********************************************************************/
-
-cl_object
-make_stream(cl_object host, int fd, enum ecl_smmode smm)
-{
-   cl_object stream;
-   char *mode;			/* file open mode */
-   FILE *fp;			/* file pointer */
-
-   switch(smm) {
-    case smm_input:
-      mode = "r";
-      break;
-    case smm_output:
-      mode = "w";
-      break;
-    default:
-      FEerror("make_stream: wrong mode", 0);
-   }
-   fp = fdopen(fd, mode);
-
-   stream = cl_alloc_object(t_stream);
-   stream->stream.mode = (short)smm;
-   stream->stream.file = fp;
-   stream->stream.object0 = @'base-char';
-   stream->stream.object1 = host; /* not really used */
-   stream->stream.int0 = stream->stream.int1 = 0;
-#if !defined(GBC_BOEHM)
-   fp->_IO_buf_base = NULL; /* BASEFF */; 
-   setbuf(fp, stream->stream.buffer = cl_alloc_atomic(BUFSIZ)); 
-#endif
-   return(stream);
-}
-
 /***********************************************************************
  * Public interface to lisp environment
  **********************************************************************/
@@ -252,8 +216,8 @@ si_open_client_stream(cl_object host, cl_object port)
    if (fd == 0)
      @(return Cnil)
 
-   streamIn = make_stream(host, fd, smm_input);
-   streamOut = make_stream(host, fd, smm_output);
+   streamIn = ecl_make_stream_from_fd(host, fd, smm_input);
+   streamOut = ecl_make_stream_from_fd(host, fd, smm_output);
 
    @(return make_two_way_stream(streamIn, streamOut))
 }
@@ -272,8 +236,8 @@ si_open_server_stream(cl_object port)
    if (fd == 0)
      output = Cnil;
    else {
-     streamIn = make_stream(Cnil, fd, smm_input);
-     streamOut = make_stream(Cnil, fd, smm_output);
+     streamIn = ecl_make_stream_from_fd(Cnil, fd, smm_input);
+     streamOut = ecl_make_stream_from_fd(Cnil, fd, smm_output);
      output = make_two_way_stream(streamIn, streamOut);
    }
    @(return output)
@@ -311,8 +275,8 @@ si_open_unix_socket_stream(cl_object path)
 		@(return Cnil)
 	}
 
-	streamIn = make_stream(path, fd, smm_input);
-	streamOut = make_stream(path, fd, smm_output);
+	streamIn = ecl_make_stream_from_fd(path, fd, smm_input);
+	streamOut = ecl_make_stream_from_fd(path, fd, smm_output);
 
 	@(return make_two_way_stream(streamIn, streamOut))
 }
diff --git a/src/c/unixsys.d b/src/c/unixsys.d
index 6b83b21a6..abf790290 100644
--- a/src/c/unixsys.d
+++ b/src/c/unixsys.d
@@ -15,6 +15,7 @@
 */
 
 #include <stdlib.h>
+#include <fcntl.h>
 #include "ecl.h"
 #include "internal.h"
 
@@ -67,3 +68,93 @@ si_close_pipe(cl_object stream)
 	}
 	@(return)
 }
+
+@(defun ext::run-program (command argv &key (input @':stream') (output @':stream')
+	  		  (error @'nil'))
+	cl_object input_pipe_read, input_pipe_write;
+	cl_object output_pipe_read, output_pipe_write;
+	int input_pipe[2], output_pipe[2];
+	int child_stdin, child_stdout, child_stderr;
+	int parent_write = 0, parent_read = 0;
+	int child_pid;
+	cl_object stream_write;
+	cl_object stream_read;
+@{
+	if (input == @':stream') {
+		int fd[2];
+		pipe(fd);
+		parent_write = fd[1];
+		child_stdin = fd[0];
+	} else if (input == @'t') {
+		child_stdin = dup(0);
+	} else {
+		child_stdin = open("/dev/null", O_RDONLY);
+	}
+	if (output == @':stream') {
+		int fd[2];
+		pipe(fd);
+		parent_read = fd[0];
+		child_stdout = fd[1];
+	} else if (output == @'t') {
+		child_stdout = dup(1);
+	} else {
+		child_stdout = open("/dev/null", O_WRONLY);
+	}
+	if (error == @'t') {
+		child_stderr = dup(2);
+	} else {
+		child_stderr = open("/dev/null", O_WRONLY);
+	}
+	command = cl_string(command);
+	argv = cl_mapcar(2, @'string', argv);
+	argv = CONS(command, nconc(argv, CONS(Cnil, Cnil)));
+	argv = cl_funcall(3, @'coerce', argv, @'vector');
+	child_pid = fork();
+	if (child_pid == 0) {
+		/* Child */
+		int j;
+		void **argv_ptr = (void **)argv->vector.self.t;
+		close(0);
+		dup(child_stdin);
+		if (parent_write) close(parent_write);
+		close(1);
+		dup(child_stdout);
+		if (parent_read) close(parent_read);
+		close(2);
+		dup(child_stderr);
+		for (j = 0; j < argv->vector.fillp; j++) {
+			cl_object arg = argv->vector.self.t[j];
+			if (arg == Cnil) {
+				argv_ptr[j] = NULL;
+			} else {
+				argv_ptr[j] = arg->string.self;
+			}
+		}
+		execv(command->string.self, (const char **)argv_ptr);
+	} else {
+		/* Parent */
+		close(child_stdin);
+		close(child_stdout);
+		close(child_stderr);
+		if (child_pid < 0) {
+			if (parent_write) close(parent_write);
+			if (parent_read) close(parent_read);
+			FEerror("Could not spawn subprocess to run ~S.", 1, command);
+		}
+		if (parent_write) {
+			stream_write = ecl_make_stream_from_fd(command, parent_write,
+							       smm_output);
+		} else {
+			stream_write = cl_core.null_stream;
+		}
+		if (parent_read) {
+			stream_read = ecl_make_stream_from_fd(command, parent_read,
+							      smm_input);
+		} else {
+			stream_read = cl_core.null_stream;
+		}
+	}
+	@(return ((parent_read || parent_write)?
+		  make_two_way_stream(stream_write, stream_read) :
+		  Cnil))
+@)
diff --git a/src/h/external.h b/src/h/external.h
index eb8b513b9..ff973fda5 100644
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -534,6 +534,7 @@ extern long file_position(cl_object strm);
 extern long file_position_set(cl_object strm, long disp);
 extern long file_length(cl_object strm);
 extern int file_column(cl_object strm);
+extern cl_object ecl_make_stream_from_fd(cl_object host, int fd, enum ecl_smmode smm);
 
 
 /* format.c */
@@ -1314,7 +1315,6 @@ extern cl_object si_open_client_stream(cl_object host, cl_object port);
 extern cl_object si_open_server_stream(cl_object port);
 extern cl_object si_open_unix_socket_stream(cl_object path);
 extern cl_object si_lookup_host_entry(cl_object host_or_address);
-extern cl_object make_stream(cl_object host, int fd, enum ecl_smmode smm);
 #endif
 
 
@@ -1430,6 +1430,7 @@ extern cl_object si_check_pending_interrupts(void);
 extern cl_object si_system(cl_object cmd);
 extern cl_object si_open_pipe(cl_object cmd);
 extern cl_object si_close_pipe(cl_object stream);
+extern cl_object si_run_program _ARGS((int narg, cl_object command, cl_object args, ...));
 
 #ifdef __cplusplus
 }