diff --git a/config.h b/config.h
new file mode 100644
index 0000000..f9d7000
--- /dev/null
+++ b/config.h
@@ -0,0 +1,27 @@
+#define HAVE_ATEXIT 1
+#define HAVE_ERRNO_H 1
+#define HAVE_FCNTL_H 1
+#define HAVE_INTTYPES_H 1
+#define HAVE_LIBSDL 1
+#define HAVE_MALLOC 1
+#define HAVE_MEMORY_H 1
+#define HAVE_MEMSET 1
+#define HAVE_RAND 1
+#define HAVE_STDINT_H 1
+#define HAVE_STDLIB_H 1
+#define HAVE_STRINGS_H 1
+#define HAVE_STRING_H 1
+#define HAVE_STRRCHR 1
+#define HAVE_SYS_IOCTL_H 1
+#define HAVE_SYS_STAT_H 1
+#define HAVE_SYS_TIME_H 1
+#define HAVE_SYS_TYPES_H 1
+#define HAVE_UNISTD_H 1
+#define PACKAGE "xsoldier"
+#define PACKAGE_NAME "xsoldier"
+#define PACKAGE_STRING "xsoldier 1.8"
+#define PACKAGE_TARNAME "xsoldier"
+#define PACKAGE_VERSION "1.8"
+#define STDC_HEADERS 1
+#define VERSION "1.8"
+#define X_DISPLAY_MISSING 1
diff --git a/ending.c b/ending.c
index 615d035..b730e44 100644
--- a/ending.c
+++ b/ending.c
@@ -72,9 +72,13 @@ void Ending(void)
 
     while (1)
     {
+#ifdef __EMSCRIPTEN__
+        fredy_frame_wait();
+#else
         if (waittime && (signal_delivered==0))
 	    pause();
         signal_delivered = 0;
+#endif
 
 	if (count < time)
         {
diff --git a/extern.h b/extern.h
index 3102a88..8fc871a 100644
--- a/extern.h
+++ b/extern.h
@@ -27,6 +27,12 @@
 EXTERN int signal_delivered;
 EXTERN int waittime;
 
+#ifdef __EMSCRIPTEN__
+/* fredy.c */
+extern void fredy_frame_wait(void);
+extern SDL_Surface *fredy_load_xpm(const char *filename);
+#endif
+
 #ifdef HAVE_LIBSDL
 EXTERN SDL_Surface *dpy;
 EXTERN SDL_Event event;
diff --git a/fredy-x11/X11/Xlib.h b/fredy-x11/X11/Xlib.h
new file mode 100644
index 0000000..61155cb
--- /dev/null
+++ b/fredy-x11/X11/Xlib.h
@@ -0,0 +1 @@
+/* Empty stand-in: the SDL build does not use X11 (see fredy.c). */
diff --git a/fredy-x11/X11/Xutil.h b/fredy-x11/X11/Xutil.h
new file mode 100644
index 0000000..61155cb
--- /dev/null
+++ b/fredy-x11/X11/Xutil.h
@@ -0,0 +1 @@
+/* Empty stand-in: the SDL build does not use X11 (see fredy.c). */
diff --git a/fredy-x11/X11/keysym.h b/fredy-x11/X11/keysym.h
new file mode 100644
index 0000000..61155cb
--- /dev/null
+++ b/fredy-x11/X11/keysym.h
@@ -0,0 +1 @@
+/* Empty stand-in: the SDL build does not use X11 (see fredy.c). */
diff --git a/fredy-x11/X11/xpm.h b/fredy-x11/X11/xpm.h
new file mode 100644
index 0000000..61155cb
--- /dev/null
+++ b/fredy-x11/X11/xpm.h
@@ -0,0 +1 @@
+/* Empty stand-in: the SDL build does not use X11 (see fredy.c). */
diff --git a/fredy.c b/fredy.c
new file mode 100644
index 0000000..64ff922
--- /dev/null
+++ b/fredy.c
@@ -0,0 +1,163 @@
+/* fredy.c: what xsoldier needs to run in a browser (Emscripten), for fredygames.com.
+ *
+ *   - fredy_load_xpm(): reads the game's XPM sprites into SDL surfaces. The game normally uses SDL_image for
+ *     this; Emscripten's SDL_image cannot read XPM, so this reads the format the sprites use (one character
+ *     per color, "#RRRRGGGGBBBB" or "None") itself. Transparent ("None") pixels and black pixels, which the
+ *     game treats as transparent through a color key that Emscripten's SDL leaves out, get alpha 0.
+ *   - fredy_frame_wait(): the game waits for the next frame with a timer signal and pause(), which a browser
+ *     does not have. Here the wait is a sleep until 35 ms after the last frame (the game's own WAIT), done with
+ *     Asyncify so the browser keeps drawing and reading the keyboard.
+ *
+ * Copyright (C) 2026 FredyGames. Distributed under the GNU General Public License, version 2 or (at your
+ * option) any later version, like xsoldier.
+ */
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <emscripten.h>
+#include <SDL.h>
+
+#include "xsoldier.h"
+
+extern int waittime; /* extern.h */
+
+static double next_frame = 0;
+
+void fredy_frame_wait(void)
+{
+  double now = emscripten_get_now();
+  double step = (waittime > 0 ? waittime : WAIT) / 1000.0;
+
+  if (next_frame == 0 || now - next_frame > 250)
+    next_frame = now;
+  next_frame += step;
+  if (next_frame > now)
+    emscripten_sleep((unsigned int)(next_frame - now + 0.5));
+  else
+    emscripten_sleep(0);
+}
+
+static int hex(int c)
+{
+  if (c >= '0' && c <= '9') return c - '0';
+  if (c >= 'a' && c <= 'f') return c - 'a' + 10;
+  if (c >= 'A' && c <= 'F') return c - 'A' + 10;
+  return -1;
+}
+
+typedef struct { char key; Uint32 argb; } XpmColor;
+
+SDL_Surface *fredy_load_xpm(const char *filename)
+{
+  FILE *fp = fopen(filename, "rb");
+  long size;
+  char *buf;
+  char *p, *end;
+  int w, h, ncolors, cpp, i, x, y;
+  XpmColor *colors;
+  SDL_Surface *surf;
+  Uint32 *pix;
+
+  if (fp == NULL)
+    return NULL;
+  fseek(fp, 0, SEEK_END);
+  size = ftell(fp);
+  fseek(fp, 0, SEEK_SET);
+  buf = (char *)malloc(size + 1);
+  if (buf == NULL || fread(buf, 1, size, fp) != (size_t)size)
+  {
+    fclose(fp);
+    free(buf);
+    return NULL;
+  }
+  fclose(fp);
+  buf[size] = '\0';
+  end = buf + size;
+
+  /* the strings of the C array: the first is the header, then the colors, then one string per row */
+#define NEXT_STRING(dst)                                      \
+  do {                                                        \
+    while (p < end && *p != '"') p++;                         \
+    if (p >= end) goto fail;                                  \
+    (dst) = ++p;                                              \
+    while (p < end && *p != '"') p++;                         \
+    if (p >= end) goto fail;                                  \
+    *p++ = '\0';                                              \
+  } while (0)
+
+  p = strstr(buf, "static");
+  if (p == NULL)
+    goto fail;
+  {
+    char *s;
+    NEXT_STRING(s);
+    if (sscanf(s, "%d %d %d %d", &w, &h, &ncolors, &cpp) != 4 || cpp != 1 || w <= 0 || h <= 0 || ncolors <= 0)
+      goto fail;
+  }
+  colors = (XpmColor *)calloc(ncolors, sizeof(XpmColor));
+  for (i = 0; i < ncolors; i++)
+  {
+    char *s, *c;
+    NEXT_STRING(s);
+    colors[i].key = s[0];
+    c = strstr(s + 1, " c ");
+    if (c == NULL)
+      c = strstr(s + 1, "\tc ");
+    if (c == NULL)
+      goto fail2;
+    c += 3;
+    if (*c == '#')
+    {
+      int n = (int)strlen(c + 1), r, g, b;
+      if (n == 12)
+      {
+        r = hex(c[1]) * 16 + hex(c[2]);
+        g = hex(c[5]) * 16 + hex(c[6]);
+        b = hex(c[9]) * 16 + hex(c[10]);
+      }
+      else if (n == 6)
+      {
+        r = hex(c[1]) * 16 + hex(c[2]);
+        g = hex(c[3]) * 16 + hex(c[4]);
+        b = hex(c[5]) * 16 + hex(c[6]);
+      }
+      else
+        goto fail2;
+      /* black is the game's color key */
+      colors[i].argb = (r == 0 && g == 0 && b == 0) ? 0 : (0xff000000u | (r << 16) | (g << 8) | b);
+    }
+    else
+      colors[i].argb = 0; /* None */
+  }
+
+  surf = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32, 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
+  if (surf == NULL)
+    goto fail2;
+  SDL_LockSurface(surf);
+  pix = (Uint32 *)surf->pixels;
+  for (y = 0; y < h; y++)
+  {
+    char *row;
+    NEXT_STRING(row);
+    for (x = 0; x < w; x++)
+    {
+      Uint32 v = 0;
+      for (i = 0; i < ncolors; i++)
+        if (colors[i].key == row[x]) { v = colors[i].argb; break; }
+      pix[y * (surf->pitch / 4) + x] = v;
+    }
+  }
+  SDL_UnlockSurface(surf);
+  free(colors);
+  free(buf);
+  return surf;
+
+fail2:
+  free(colors);
+fail:
+  free(buf);
+  return NULL;
+}
diff --git a/game.c b/game.c
index 3481bcf..bf34554 100644
--- a/game.c
+++ b/game.c
@@ -99,9 +99,13 @@ int mainLoop(void)
 #endif /* not HAVE_LIBSDL */
     while (1)
     {
+#ifdef __EMSCRIPTEN__
+        fredy_frame_wait();
+#else
         if (waittime && (signal_delivered==0))
 	    pause();
         signal_delivered = 0;
+#endif
 
         if (event_handle() == 0)
           return 0;
diff --git a/image.c b/image.c
index a783573..795c173 100644
--- a/image.c
+++ b/image.c
@@ -45,7 +45,11 @@ void ReadFileToImage(const char *filename, Image **img)
 {
 #ifdef HAVE_LIBSDL
   SDL_Surface *temp;
+#ifdef __EMSCRIPTEN__
+  temp = fredy_load_xpm(filename);
+#else
   temp = IMG_Load(filename);
+#endif
   if (temp == NULL)
   {
     fprintf(stderr, "ReadFileToImage: IMG_Load(%s) failed (%s)\n",
diff --git a/input.c b/input.c
index b5744f1..4394163 100644
--- a/input.c
+++ b/input.c
@@ -42,7 +42,18 @@ int input_init(void)
   initJS();
 #endif /* JSTK */
 
-#ifdef HAVE_LIBSDL
+#ifdef __EMSCRIPTEN__
+  /* the SDL 1.2 of the browser has no key names */
+  upKey    = "Up";
+  downKey  = "Down";
+  leftKey  = "Left";
+  rightKey = "Right";
+  shotKey  = "Left Shift";
+  spdupKey = "a";
+  spdwnKey = "s";
+  pauseKey = "p";
+  quitKey  = "q";
+#elif defined(HAVE_LIBSDL)
   upKey    = SDL_GetKeyName(SDLK_UP);
   downKey  = SDL_GetKeyName(SDLK_DOWN);
   leftKey  = SDL_GetKeyName(SDLK_LEFT);
diff --git a/main.c b/main.c
index e5cdc1e..3a14f16 100644
--- a/main.c
+++ b/main.c
@@ -392,6 +392,7 @@ static void init(void)
     else
 	waittime = w_time;
 
+#ifndef __EMSCRIPTEN__
     memset(&sig_act, 0, sizeof(sig_act));
     sig_act.sa_handler = sig_handle;
     sigaction(SIGALRM, &sig_act, 0);
@@ -400,6 +401,7 @@ static void init(void)
     value.it_value.tv_sec = 0;
     value.it_value.tv_usec = waittime;
     setitimer(ITIMER_REAL, &value, &ovalue);
+#endif /* not __EMSCRIPTEN__ */
 
     FieldW  = 500;
     FieldH  = 650;
diff --git a/manage.c b/manage.c
index 4e4008f..e3c07e4 100644
--- a/manage.c
+++ b/manage.c
@@ -372,6 +372,11 @@ PlayerData *NewPlayerData(void)
 
     /* we don't free() the memory allocated by getpwuid() because
      * it is allocated statically */
+#ifdef __EMSCRIPTEN__
+    /* the browser has no user names */
+    pw = NULL;
+    snprintf(name, sizeof(name) - 1, "player");
+#else
     if ((pw=getpwuid(getuid())) == NULL)
         snprintf(name, sizeof(name) - 1, "%d",getuid());
     else
@@ -391,6 +396,7 @@ PlayerData *NewPlayerData(void)
 
 
     }
+#endif /* not __EMSCRIPTEN__ */
 
     New = (PlayerData *)malloc(sizeof(PlayerData));
 
diff --git a/opening.c b/opening.c
index f881983..0163174 100644
--- a/opening.c
+++ b/opening.c
@@ -44,9 +44,13 @@ int Opening(void)
 
     while(1)
     {
+#ifdef __EMSCRIPTEN__
+        fredy_frame_wait();
+#else
         if (waittime && (signal_delivered==0))
 	    pause();
         signal_delivered = 0;
+#endif
 
 	if (count < 500)
 	    count++;