Windows seems to think standards are more suggestions than actual rules.

POSIX says return -1 on error. Windows returns whatever it feels like.
  => listen/accept/getaddrinfo all now compare for equality to 0
Windows also needs a call to WSAStartup before networking

api/glue/socket.c

@@ -37,6 +37,10 @@
 #include "../memory/memory.h"
 #include "../format/format.h"
 
+#ifdef __WIN32
+#include <winsock2.h>
+#endif
+
 const char* eb_status(eb_status_t code) {
   switch (code) {
   case EB_OK:       return "success";
@@ -62,6 +66,10 @@ eb_status_t eb_socket_open(uint16_t abi_code, const char* port, eb_width_t suppo
   struct eb_socket_aux* aux;
   eb_status_t status;
   uint8_t link_type;
+#ifdef  __WIN32
+  WORD wVersionRequested;
+  WSADATA wsaData;
+#endif
   
   /* Does the library support the application? */
   if (abi_code != EB_ABI_CODE)
@@ -94,6 +102,15 @@ eb_status_t eb_socket_open(uint16_t abi_code, const char* port, eb_width_t suppo
     return EB_OOM;
   }
   
+#ifdef __WIN32
+  wVersionRequested = MAKEWORD(2, 2);
+  if (WSAStartup(wVersionRequested, &wsaData) != 0) {
+    eb_free_socket(socketp);
+    eb_free_socket_aux(auxp);
+    return EB_FAIL;
+  }
+#endif
+  
   /* Allocate the transports */
   status = EB_OK;
   first_transport = EB_NULL;
@@ -205,6 +222,10 @@ eb_status_t eb_socket_close(eb_socket_t socketp) {
     eb_free_transport(transportp);
   }
   
+#ifdef __WIN32
+  WSACleanup();
+#endif
+
   eb_free_socket(socketp);
   eb_free_socket_aux(auxp);
   return EB_OK;

api/tools/eb-tunnel.c

@@ -34,6 +34,10 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#ifdef __WIN32
+#include <winsock2.h>
+#endif
+
 struct eb_client {
   struct eb_transport udp_transport;
   struct eb_link udp_slave;
@@ -87,12 +91,24 @@ int main(int argc, const char** argv) {
   uint8_t buffer[16384];
   uint8_t len_buf[2];
   fd_set rfds;
+#ifdef  __WIN32
+  WORD wVersionRequested;
+  WSADATA wsaData;
+#endif
   
   if (argc != 2) {
     fprintf(stderr, "Syntax: %s <proxy-port>\n", argv[0]);
     return 1;
   }
   
+#ifdef __WIN32
+  wVersionRequested = MAKEWORD(2, 2);
+  if (WSAStartup(wVersionRequested, &wsaData) != 0) {
+    perror("Cannot initialize winsock");
+    return 1;
+  }
+#endif
+  
   if ((err = eb_posix_tcp_open(&tcp_transport, argv[1])) != EB_OK) {
     perror("Cannot open TCP port");
     return 1;

api/transport/posix-ip.c

@@ -62,7 +62,7 @@ eb_posix_sock_t eb_posix_ip_open(int type, const char* port) {
   hints.ai_protocol = protocol; /* TCP/UDP over IP to exclude non IPv* protocols */
   hints.ai_flags = AI_PASSIVE;  /* Suitable for binding a socket */
   
-  if (getaddrinfo(0, port?port:"0", &hints, &match) < 0)
+  if (getaddrinfo(0, port?port:"0", &hints, &match) != 0)
     return -1;
   
   for (i = match; i; i = i->ai_next) {
@@ -118,7 +118,7 @@ socklen_t eb_posix_ip_resolve(const char* prefix, const char* address, int type,
   hints.ai_protocol = protocol; /* TCP/UDP over IP to exclude non IPv* protocols */
   hints.ai_flags = 0;
   
-  if (getaddrinfo(host, port, &hints, &match) < 0)
+  if (getaddrinfo(host, port, &hints, &match) != 0)
     return -1;
   
   memcpy(out, match->ai_addr, match->ai_addrlen);

api/transport/posix-tcp.c

@@ -41,7 +41,7 @@ eb_status_t eb_posix_tcp_open(struct eb_transport* transportp, const char* port)
   sock = eb_posix_ip_open(SOCK_STREAM, port);
   if (sock == -1) return EB_BUSY;
   
-  if (listen(sock, 5) < 0) {
+  if (listen(sock, 5) != 0) {
     eb_posix_ip_close(sock);
     return EB_ADDRESS; 
   }
@@ -75,7 +75,7 @@ eb_status_t eb_posix_tcp_connect(struct eb_transport* transportp, struct eb_link
   sock = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP);
   if (sock == -1) return EB_FAIL;
   
-  if (connect(sock, (struct sockaddr*)&sa, len) < 0) {
+  if (connect(sock, (struct sockaddr*)&sa, len) != 0) {
     eb_posix_ip_close(sock);
     return EB_FAIL;
   }