diff -ruN a/src/domino-chain/fribidi.h b/src/domino-chain/fribidi.h
--- a/src/domino-chain/fribidi.h
+++ b/src/domino-chain/fribidi.h
@@ -0,0 +1,63 @@
+/*
+ * Minimal stand-in for the FriBidi calls Domino Chain makes (fredygames.com browser build).
+ * It handles left-to-right text only, which is all the English interface needs: the text is
+ * converted from UTF-8 to UTF-32, every character gets the left-to-right level 0 and the line
+ * reordering leaves the line as it is.
+ */
+#ifndef FRIBIDI_SHIM_H
+#define FRIBIDI_SHIM_H
+
+#include <cstddef>
+#include <cstdint>
+
+typedef uint32_t FriBidiChar;
+typedef uint32_t FriBidiCharType;
+typedef int8_t FriBidiLevel;
+typedef int FriBidiStrIndex;
+
+#define FRIBIDI_TYPE_ON 0
+#define FRIBIDI_TYPE_LTR 0
+#define FRIBIDI_CHAR_SET_UTF8 1
+#define FRIBIDI_FLAGS_DEFAULT 0
+
+static inline FriBidiStrIndex fribidi_charset_to_unicode(int, const char *s, FriBidiStrIndex len, FriBidiChar *out)
+{
+  FriBidiStrIndex n = 0;
+  for (FriBidiStrIndex i = 0; i < len;)
+  {
+    unsigned char c = (unsigned char)s[i];
+    uint32_t cp;
+    int extra;
+    if (c < 0x80) { cp = c; extra = 0; }
+    else if ((c >> 5) == 6) { cp = c & 0x1F; extra = 1; }
+    else if ((c >> 4) == 14) { cp = c & 0x0F; extra = 2; }
+    else if ((c >> 3) == 30) { cp = c & 0x07; extra = 3; }
+    else { cp = 0xFFFD; extra = 0; }
+    i++;
+    for (int k = 0; k < extra && i < len && ((unsigned char)s[i] >> 6) == 2; k++, i++)
+      cp = (cp << 6) | ((unsigned char)s[i] & 0x3F);
+    out[n++] = cp;
+  }
+  return n;
+}
+
+static inline void fribidi_get_bidi_types(const FriBidiChar *, FriBidiStrIndex len, FriBidiCharType *types)
+{
+  for (FriBidiStrIndex i = 0; i < len; i++) types[i] = FRIBIDI_TYPE_LTR;
+}
+
+static inline FriBidiLevel fribidi_get_par_embedding_levels(const FriBidiCharType *, FriBidiStrIndex len,
+                                                            FriBidiCharType *base, FriBidiLevel *levels)
+{
+  *base = FRIBIDI_TYPE_LTR;
+  for (FriBidiStrIndex i = 0; i < len; i++) levels[i] = 0;
+  return 1;
+}
+
+static inline FriBidiLevel fribidi_reorder_line(int, const FriBidiCharType *, FriBidiStrIndex, FriBidiStrIndex,
+                                                FriBidiCharType, FriBidiLevel *, FriBidiChar *, FriBidiStrIndex *)
+{
+  return 1;
+}
+
+#endif
diff -ruN a/src/domino-chain/graphicsn.cpp b/src/domino-chain/graphicsn.cpp
--- a/src/domino-chain/graphicsn.cpp
+++ b/src/domino-chain/graphicsn.cpp
@@ -36,7 +36,7 @@
 
 #include <assert.h>
 
-#include <boost/filesystem.hpp>
+#include <filesystem>
 
 // the following array contains the y offset to use for the different
 // images of the different figure animation images
@@ -314,7 +314,7 @@
     // constant care
     std::string figurefile;
 
-    if (boost::filesystem::exists(getHome() + "figure.png"))
+    if (std::filesystem::exists(getHome() + "figure.png"))
       figurefile = getHome() + "figure.png";
     else
       figurefile = dataPath+"/images/figure.png";
diff -ruN a/src/domino-chain/main.cpp b/src/domino-chain/main.cpp
--- a/src/domino-chain/main.cpp
+++ b/src/domino-chain/main.cpp
@@ -37,6 +37,9 @@
 
 #include <sys/stat.h>
 #include <libintl.h>
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
 
 static std::string getDataDir(void)
 {
@@ -261,6 +264,10 @@
         while (SDL_GetTicks() < ticks)
           SDL_Delay(ticks-SDL_GetTicks());
       }
+#ifdef __EMSCRIPTEN__
+      // hand the turn back to the browser, which paints and delivers input in between
+      emscripten_sleep(0);
+#endif
 
       while (true) {
 
diff -ruN a/src/domino-chain/screen.cpp b/src/domino-chain/screen.cpp
--- a/src/domino-chain/screen.cpp
+++ b/src/domino-chain/screen.cpp
@@ -204,6 +204,16 @@
 {
   SDL_UpdateTexture(sdlTexture, NULL, video->pixels, video->pitch);
 
+#ifdef __EMSCRIPTEN__
+  // the canvas does not keep the previous frame after presenting it, so the changed blocks
+  // alone would leave everything else black: copy the whole picture every time
+  (void)dirty;
+  SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, NULL);
+  SDL_RenderPresent(sdlRenderer);
+  animationState = 0;
+  return;
+#endif
+
   for (int y = 0; y < 25; y++)
   {
     int rowStart = -1;
@@ -630,10 +640,15 @@
   }
 
   SDL_UpdateTexture(sdlTexture, NULL, video->pixels, video->pitch);
+#ifdef __EMSCRIPTEN__
+  // see flipDirty
+  SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, NULL);
+#else
   for (int i = 0; i < count; i++)
   {
       SDL_RenderCopy(sdlRenderer, sdlTexture, &rects[i], &rects[i]);
   }
+#endif
   SDL_RenderPresent(sdlRenderer);
 
   if (animationState == 64)
diff -ruN a/src/domino-chain/tools.cpp b/src/domino-chain/tools.cpp
--- a/src/domino-chain/tools.cpp
+++ b/src/domino-chain/tools.cpp
@@ -46,7 +46,7 @@
 
 #include <stdexcept>
 
-#include <boost/filesystem.hpp>
+#include <filesystem>
 
 uint64_t getTime(void)
 {
@@ -160,19 +160,19 @@
 
 std::string findFileInDirectory(const std::string & path, const std::string name, uint16_t depth)
 {
-  boost::filesystem::path p (path);   // p reads clearer than argv[1] in the following code
+  std::filesystem::path p (path);   // p reads clearer than argv[1] in the following code
 
   if (depth > 0)
   {
-    if (boost::filesystem::exists(p))
+    if (std::filesystem::exists(p))
     {
-      if (boost::filesystem::is_regular_file(p) && p.filename() == name)
+      if (std::filesystem::is_regular_file(p) && p.filename() == name)
       {
         return p.string();
       }
-      else if (boost::filesystem::is_directory(p))
+      else if (std::filesystem::is_directory(p))
       {
-        for (boost::filesystem::directory_iterator i(p); i != boost::filesystem::directory_iterator(); ++i)
+        for (std::filesystem::directory_iterator i(p); i != std::filesystem::directory_iterator(); ++i)
         {
           std::string f = findFileInDirectory(i->path().string(), name, depth-1);