diff --git a/include/arpa/inet.h b/include/arpa/inet.h
index 99516d72a..f42508f45 100644
--- a/include/arpa/inet.h
+++ b/include/arpa/inet.h
@@ -6,6 +6,17 @@ arpa/inet.h
 #define _ARPA__INET_H
 
 /* Open Group Base Specifications Issue 6 (not complete): */
+
+#ifndef _STRUCT_IN_ADDR
+#define _STRUCT_IN_ADDR
+/* Has to match corresponding declaration in <netinet/in.h> */
+struct in_addr
+{
+	in_addr_t	s_addr;
+};
+#endif
+
+
 char *inet_ntoa(struct in_addr in);
 
 #endif /* _ARPA__INET_H */
diff --git a/include/errno.h b/include/errno.h
index 332bde28b..95b30969c 100755
--- a/include/errno.h
+++ b/include/errno.h
@@ -94,6 +94,9 @@ extern int errno;		  /* place where the error numbers go */
 #define ENOCONN       (_SIGN 66)  /* no such connection */
 #define EAFNOSUPPORT  (_SIGN 67)  /* address family not supported */
 #define EPROTONOSUPPORT  (_SIGN 68)  /* protocol not supported by AF */
+#define EPROTOTYPE    (_SIGN 69)  /* Protocol wrong type for socket */
+#define EINPROGRESS   (_SIGN 70)  /* Operation now in progress */
+#define EADDRNOTAVAIL (_SIGN 71)  /* Can't assign requested address */
 
 /* The following are not POSIX errors, but they can still happen. 
  * All of these are generated by the kernel and relate to message passing.
diff --git a/include/math.h b/include/math.h
index 48d16aa1f..1ea4b47aa 100755
--- a/include/math.h
+++ b/include/math.h
@@ -36,4 +36,8 @@ _PROTOTYPE( double sqrt,  (double _x)					);
 _PROTOTYPE( double tan,   (double _x)					);
 _PROTOTYPE( double tanh,  (double _x)					);
 
+#ifdef _POSIX_SOURCE	/* STD-C? */
+#include <mathconst.h>
+#endif
+
 #endif /* _MATH_H */
diff --git a/include/minix/config.h b/include/minix/config.h
index a43189a2b..94b244111 100755
--- a/include/minix/config.h
+++ b/include/minix/config.h
@@ -22,7 +22,6 @@
 #define SUN_4             40	/* any Sun SPARC-based system */
 #define SUN_4_60	  40	/* Sun-4/60 (aka SparcStation 1 or Campus) */
 #define ATARI             60	/* ATARI ST/STe/TT (68000/68030) */
-#define AMIGA             61	/* Commodore Amiga (68000) */
 #define MACINTOSH         62	/* Apple Macintosh (68000) */
 
 /* Word size in bytes (a constant equal to sizeof(int)). */
@@ -160,7 +159,7 @@
 #define CHIP          INTEL
 #endif
 
-#if (MACHINE == ATARI) || (MACHINE == AMIGA) || (MACHINE == MACINTOSH)
+#if (MACHINE == ATARI) || (MACHINE == MACINTOSH)
 #define CHIP         M68000
 #endif
 
diff --git a/include/net/if.h b/include/net/if.h
new file mode 100644
index 000000000..e49449acf
--- /dev/null
+++ b/include/net/if.h
@@ -0,0 +1,3 @@
+/*
+net/if.h
+*/
diff --git a/include/netinet/in.h b/include/netinet/in.h
index 11e33bde9..a1586e165 100644
--- a/include/netinet/in.h
+++ b/include/netinet/in.h
@@ -11,11 +11,47 @@ netinet/in.h
 #include <stdint.h>
 
 /* Open Group Base Specifications Issue 6 (not complete) */
-typedef uint32_t in_addr_t;
+#define    INADDR_ANY              (uint32_t)0x00000000
 
+typedef uint16_t	in_port_t;
+
+#ifndef _IN_ADDR_T
+#define _IN_ADDR_T
+typedef uint32_t	in_addr_t;
+#endif /* _IN_ADDR_T */
+
+#ifndef _SA_FAMILY_T
+#define _SA_FAMILY_T
+/* Should match corresponding typedef in <sys/socket.h> */
+typedef uint8_t		sa_family_t;
+#endif /* _SA_FAMILY_T */
+
+/* Protocols */
+#define IPPROTO_IP	0	/* Dummy protocol */
+
+/* setsockopt options at IP level */
+#define IP_ADD_MEMBERSHIP	12
+#define IP_DROP_MEMBERSHIP	13
+
+#ifndef _STRUCT_IN_ADDR
+#define _STRUCT_IN_ADDR
 struct in_addr
 {
 	in_addr_t	s_addr;
 };
+#endif
+
+struct sockaddr_in
+{
+	sa_family_t	sin_family;
+	in_port_t	sin_port;
+	struct in_addr	sin_addr;
+};
+
+struct ip_mreq
+{
+	struct  in_addr imr_multiaddr;
+	struct  in_addr imr_interface;
+};
 
 #endif /* _NETINET__IN_H */
diff --git a/include/netinet/tcp.h b/include/netinet/tcp.h
new file mode 100644
index 000000000..e69de29bb
diff --git a/include/stdlib.h b/include/stdlib.h
index 2e42cc1a5..827a69164 100755
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -64,11 +64,21 @@ _PROTOTYPE( unsigned long int strtoul,
 			(const char *_nptr, char **_endptr, int _base)	);
 
 #ifdef _POSIX_SOURCE
+/* Open Group Base Specifications Issue 6 */
 _PROTOTYPE( int mkstemp, (char *_fmt)					);
+_PROTOTYPE( char *initstate, (unsigned _seed, char *_state,
+							size_t _size)	);
+_PROTOTYPE( long random, (void)						);
+_PROTOTYPE( char *setstate, (const char *state)				);
+_PROTOTYPE( void srandom, (unsigned seed)				);
 #endif
 
 #ifdef _MINIX
 _PROTOTYPE( int putenv, (const char *_name)				);
+
+/* According to POSIX, getopt should be in unistd.h. What do we do with
+ * this?
+ */
 _PROTOTYPE(int getopt, (int _argc, char **_argv, char *_opts));
 extern char *optarg;
 extern int optind, opterr, optopt;
diff --git a/include/string.h b/include/string.h
index bd93957d2..5594922b2 100755
--- a/include/string.h
+++ b/include/string.h
@@ -40,6 +40,11 @@ _PROTOTYPE( char *strstr, (const char *_s1, const char *_s2)		);
 _PROTOTYPE( char *strtok, (char *_s1, const char *_s2)			);
 _PROTOTYPE( size_t strxfrm, (char *_s1, const char *_s2, size_t _n)	);
 
+#ifdef _POSIX_SOURCE
+/* Open Group Base Specifications Issue 6 (not complete) */
+ char *strdup(const char *_s1);
+#endif
+
 #ifdef _MINIX
 /* For backward compatibility. */
 _PROTOTYPE( char *index, (const char *_s, int _charwanted)		);
@@ -49,6 +54,7 @@ _PROTOTYPE( int bcmp, (const void *_s1, const void *_s2, size_t _length));
 _PROTOTYPE( void bzero, (void *_dst, size_t _length)			);
 _PROTOTYPE( void *memccpy, (char *_dst, const char *_src, int _ucharstop,
 						    size_t _size)	);
+
 /* Misc. extra functions */
 _PROTOTYPE( int strcasecmp, (const char *_s1, const char *_s2)		);
 _PROTOTYPE( int strncasecmp, (const char *_s1, const char *_s2,
diff --git a/include/sys/ioc_file.h b/include/sys/ioc_file.h
new file mode 100755
index 000000000..735bfe726
--- /dev/null
+++ b/include/sys/ioc_file.h
@@ -0,0 +1,11 @@
+/*	sys/ioc_file.h - File ioctl() command codes.
+ */
+
+#ifndef _SYS_IOC_FILE_H
+#define _SYS_IOC_FILE_H
+
+#include <minix/ioctl.h>
+
+#define FIONREAD	_IOR('f', 1, int)
+
+#endif /* _SYS_IOC_FILE_H */
diff --git a/include/sys/ioctl.h b/include/sys/ioctl.h
index f49b88236..2cfb735d8 100755
--- a/include/sys/ioctl.h
+++ b/include/sys/ioctl.h
@@ -16,6 +16,7 @@
 #include <sys/ioc_tty.h>	/* 'T' 't' 'k'		*/
 #include <net/ioctl.h>		/* 'n'			*/
 #include <sys/ioc_disk.h>	/* 'd'			*/
+#include <sys/ioc_file.h>	/* 'f'			*/
 #include <sys/ioc_memory.h>	/* 'm'			*/
 #include <sys/ioc_tape.h>	/* 'M'			*/
 #include <sys/ioc_scsi.h>	/* 'S'			*/
diff --git a/include/sys/param.h b/include/sys/param.h
new file mode 100644
index 000000000..0ef24f643
--- /dev/null
+++ b/include/sys/param.h
@@ -0,0 +1,7 @@
+/*
+sys/param.h
+*/
+
+/* Do we need this header file? Maybe an empty one is sufficient to avoid
+ * compilations errors.
+ */
diff --git a/include/sys/select.h b/include/sys/select.h
index a27ac59f5..67c1eb99e 100755
--- a/include/sys/select.h
+++ b/include/sys/select.h
@@ -8,10 +8,10 @@
 #include <string.h>
 
 /* Use this datatype as basic storage unit in fd_set */
-typedef u32_t _fdsetword;	
+typedef u32_t fd_mask;	
 
 /* This many bits fit in an fd_set word. */
-#define _FDSETBITSPERWORD	(sizeof(_fdsetword)*8)
+#define _FDSETBITSPERWORD	(sizeof(fd_mask)*8)
 
 /* Bit manipulation macros */
 #define _FD_BITMASK(b)	(1L << ((b) % _FDSETBITSPERWORD))
@@ -26,7 +26,7 @@ typedef u32_t _fdsetword;
 #define _FDSETWORDS	((FD_SETSIZE+_FDSETBITSPERWORD-1)/_FDSETBITSPERWORD)
 
 typedef struct {
-	_fdsetword	_fdsetval[_FDSETWORDS];
+	fd_mask	fds_bits[_FDSETWORDS];
 } fd_set;
 
 _PROTOTYPE( int select, (int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout) );
diff --git a/include/sys/socket.h b/include/sys/socket.h
index e2c642e9c..6aaada3ac 100644
--- a/include/sys/socket.h
+++ b/include/sys/socket.h
@@ -2,5 +2,66 @@
 sys/socket.h
 */
 
+#ifndef SYS_SOCKET_H
+#define SYS_SOCKET_H
+
+/* Can we include <stdint.h> here or do we need an additional header that is
+ * safe to include?
+ */
+#include <stdint.h>
+
 /* Open Group Base Specifications Issue 6 (not complete) */
 #include <net/gen/socket.h>
+
+#define SOCK_STREAM	1
+#define SOCK_DGRAM	2
+
+#define SOL_SOCKET	0xFFFF
+
+#define SO_REUSEADDR	0x0004
+#define SO_KEEPALIVE	0x0008
+
+/* The how argument to shutdown */
+#define SHUT_RD		0	/* No further reads */
+#define SHUT_WR		1	/* No further writes */
+#define SHUT_RDWR	2	/* No further reads and writes */
+
+#ifndef _SA_FAMILY_T
+#define _SA_FAMILY_T
+typedef uint8_t		sa_family_t;
+#endif /* _SA_FAMILY_T */
+
+typedef int32_t socklen_t;
+
+struct sockaddr
+{
+	sa_family_t	sa_family;
+	char		sa_data[1];
+};
+
+_PROTOTYPE( int accept, (int _socket,
+				struct sockaddr *_RESTRICT _address,
+				socklen_t *_RESTRICT _address_len)	);
+_PROTOTYPE( int bind, (int _socket, const struct sockaddr *_address,
+						socklen_t _address_len)	);
+_PROTOTYPE( int connect, (int _socket, const struct sockaddr *_address,
+						socklen_t _address_len)	);
+_PROTOTYPE( int getpeername, (int _socket,
+				struct sockaddr *_RESTRICT _address,
+				socklen_t *_RESTRICT _address_len)	);
+_PROTOTYPE( int getsockname, (int _socket,
+				struct sockaddr *_RESTRICT _address,
+				socklen_t *_RESTRICT _address_len)	);
+_PROTOTYPE( int setsockopt,(int _socket, int _level, int _option_name,
+		const void *_option_value, socklen_t _option_len)	);
+_PROTOTYPE( int listen, (int _socket, int _backlog)			);
+_PROTOTYPE( ssize_t recvfrom, (int _socket, void *_RESTRICT _buffer,
+	size_t _length, int _flags, struct sockaddr *_RESTRICT _address,
+				socklen_t *_RESTRICT _address_len)	);
+_PROTOTYPE( ssize_t sendto, (int _socket, const void *_message,
+	size_t _length, int _flags, const struct sockaddr *_dest_addr,
+						socklen_t _dest_len)	);
+_PROTOTYPE( int shutdown, (int _socket, int _how)			);
+_PROTOTYPE( int socket, (int _domain, int _type, int _protocol)		);
+
+#endif /* SYS_SOCKET_H */
diff --git a/include/sys/uio.h b/include/sys/uio.h
new file mode 100644
index 000000000..d4dba19a3
--- /dev/null
+++ b/include/sys/uio.h
@@ -0,0 +1,23 @@
+/*
+sys/uio.h
+
+definitions for vector I/O operations
+*/
+
+#ifndef _SYS_UIO_H
+#define _SYS_UIO_H
+
+/* Open Group Base Specifications Issue 6 (not complete) */
+
+struct iovec
+{
+	void	*iov_base;
+	size_t	iov_len;
+};
+
+_PROTOTYPE(ssize_t readv, (int _fildes, const struct iovec *_iov,
+							int _iovcnt)	);
+_PROTOTYPE(ssize_t writev, (int _fildes, const struct iovec *_iov,
+							int iovcnt)	);
+
+#endif /* _SYS_UIO_H */
diff --git a/include/sys/un.h b/include/sys/un.h
new file mode 100644
index 000000000..5a38e3ce8
--- /dev/null
+++ b/include/sys/un.h
@@ -0,0 +1,19 @@
+/*
+sys/un.h
+*/
+
+/* Open Group Base Specifications Issue 6 */
+
+#ifndef SA_FAMILY_T
+#define SA_FAMILY_T
+/* Should match corresponding typedef in <sys/socket.h> */
+typedef uint8_t		sa_family_t;
+#endif /* SA_FAMILY_T */
+
+struct sockaddr_un
+{
+	sa_family_t	sun_family;
+	char		sun_path[127];
+};
+
+/* Note: UNIX domain sockets are not implemented! */
diff --git a/include/unistd.h b/include/unistd.h
index d23249c0b..aca86a3ad 100755
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -133,6 +133,10 @@ _PROTOTYPE( ssize_t write, (int _fd, const void *_buf, size_t _n)	);
 
 /* Open Group Base Specifications Issue 6 (not complete) */
 _PROTOTYPE( int symlink, (const char *path1, const char *path2)		);
+_PROTOTYPE( int getopt, (int _argc, char **_argv, char *_opts)		);
+extern char *optarg;
+extern int optind, opterr, optopt;
+_PROTOTYPE( int usleep, (useconds_t _useconds)				);
 
 #ifdef _MINIX
 #ifndef _TYPE_H