diff --git a/kilo.c b/kilo.c
index 2514ec3..7736da2 100644
--- a/kilo.c
+++ b/kilo.c
@@ -41,6 +41,9 @@ enum editorKey {
 enum editorHighlight {
   HL_NORMAL = 0,
   HL_COMMENT,
+  HL_MLCOMMENT,
+  HL_KEYWORD1,
+  HL_KEYWORD2,
   HL_STRING,
   HL_NUMBER,
   HL_MATCH
@@ -55,16 +58,21 @@ enum editorHighlight {
 struct editorSyntax {
   char *filetype;
   char **filematch;
+  char **keywords;
   char *singleline_comment_start;
+  char *multiline_comment_start;
+  char *multiline_comment_end;
   int flags;
 };
 
 typedef struct erow {
+  int idx;
   int size;
   int rsize;
   char *chars;
   char *render;
   unsigned char *hl;
+  int hl_open_comment;
 } erow;
 
 struct editorConfig {
@@ -89,12 +97,20 @@ struct editorConfig E;
 /*** filetypes ***/
 
 char *C_HL_extensions[] = { ".c", ".h", ".cpp", NULL };
+char *C_HL_keywords[] = {
+  "switch", "if", "while", "for", "break", "continue", "return", "else",
+  "struct", "union", "typedef", "static", "enum", "class", "case",
+
+  "int|", "long|", "double|", "float|", "char|", "unsigned|", "signed|",
+  "void|", NULL
+};
 
 struct editorSyntax HLDB[] = {
   {
     "c",
     C_HL_extensions,
-    "//",
+    C_HL_keywords,
+    "//", "/*", "*/",
     HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
   },
 };
@@ -236,11 +252,19 @@ void editorUpdateSyntax(erow *row) {
 
   if (E.syntax == NULL) return;
 
+  char **keywords = E.syntax->keywords;
+
   char *scs = E.syntax->singleline_comment_start;
+  char *mcs = E.syntax->multiline_comment_start;
+  char *mce = E.syntax->multiline_comment_end;
+
   int scs_len = scs ? strlen(scs) : 0;
+  int mcs_len = mcs ? strlen(mcs) : 0;
+  int mce_len = mce ? strlen(mce) : 0;
 
   int prev_sep = 1;
   int in_string = 0;
+  int in_comment = (row->idx > 0 && E.row[row->idx-1].hl_open_comment);
 
   int i = 0;
   while (i < row->rsize) {
@@ -248,13 +272,35 @@ void editorUpdateSyntax(erow *row) {
     unsigned char prev_hl = (i > 0) ? row->hl[i -1] : HL_NORMAL;
 
     // Comments
-    if (scs_len && !in_string) {
+    if (scs_len && !in_string && !in_comment) {
       if (!strncmp(&row->render[i], scs, scs_len)) {
         memset(&row->hl[i], HL_COMMENT, row->rsize - i);
         break;
       }
     }
 
+    // Multi line comments
+    if (mcs_len && mce_len && !in_string) {
+      if (in_comment) {
+        row->hl[i] = HL_MLCOMMENT;
+        if (!strncmp(&row->render[i], mce, mce_len)) {
+          memset(&row->hl[i], HL_MLCOMMENT, mce_len);
+          i += mce_len;
+          in_comment = 0;
+          prev_sep = 1;
+          continue;
+        } else {
+          i++;
+          continue;
+        }
+      } else if (!strncmp(&row->render[i], mcs, mcs_len)) {
+        memset(&row->hl[i], HL_MLCOMMENT, mcs_len);
+        i += mcs_len;
+        in_comment = 1;
+        continue;
+      }
+    }
+
     // Strings
     if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
       if (in_string) {
@@ -289,14 +335,44 @@ void editorUpdateSyntax(erow *row) {
       }
     }
 
+    // Keywords
+    if (prev_sep) {
+      int j;
+      for (j=0; keywords[j]; j++) {
+        int klen = strlen(keywords[j]);
+        int kw2 = keywords[j][klen - 1] == '|';
+        if (kw2) klen--;
+
+        if (!strncmp(&row->render[i], keywords[j], klen) &&
+            is_separator(row->render[i + klen])) {
+          memset(&row->hl[i], kw2 ? HL_KEYWORD2 : HL_KEYWORD1, klen);
+          i += klen;
+          break;
+        }
+      }
+      if (keywords[j] != NULL) {
+        prev_sep = 0;
+        continue;
+      }
+    }
+
     prev_sep = is_separator(c);
     i++;
   }
+
+  int changed = (row->hl_open_comment != in_comment);
+  row->hl_open_comment = in_comment;
+  if (changed && row->idx+1 < E.numrows) {
+    editorUpdateSyntax(&E.row[row->idx+1]);
+  }
 }
 
 int editorSyntaxToColor(int hl) {
   switch (hl) {
-    case HL_COMMENT: return 36;
+    case HL_COMMENT:
+    case HL_MLCOMMENT: return 36;
+    case HL_KEYWORD1: return 33;
+    case HL_KEYWORD2: return 32;
     case HL_STRING: return 35;
     case HL_NUMBER: return 31;
     case HL_MATCH: return 34;
@@ -387,6 +463,9 @@ void editorInsertRow(int at, char *s, size_t len) {
 
   E.row = realloc(E.row, sizeof(erow) * (E.numrows +1));
   memmove(&E.row[at + 1], &E.row[at], sizeof(erow) * (E.numrows - at));
+  for (int j=at+1; j<= E.numrows; j++) E.row[j].idx++;
+
+  E.row[at].idx = at;
 
   E.row[at].size = len;
   E.row[at].chars = malloc(len + 1);
@@ -396,6 +475,7 @@ void editorInsertRow(int at, char *s, size_t len) {
   E.row[at].rsize = 0;
   E.row[at].render = NULL;
   E.row[at].hl = NULL;
+  E.row[at].hl_open_comment = 0;
   editorUpdateRow(&E.row[at]);
 
   E.numrows++;
@@ -412,6 +492,7 @@ void editorDelRow(int at) {
   if (at < 0 || at >= E.numrows) return;
   editorFreeRow(&E.row[at]);
   memmove(&E.row[at], &E.row[at + 1], sizeof(erow) * (E.numrows - at -1));
+  for (int j=at; j<= E.numrows-1; j++) E.row[j].idx--;
   E.numrows--;
   E.dirty++;
 }
@@ -704,7 +785,17 @@ void editorDrawRows(struct abuf *ab) {
       int current_color = -1;
       int j;
       for (j=0; j<len; j++) {
-        if (hl[j] == HL_NORMAL) {
+        if (iscntrl(c[j])) {
+          char sym = (c[j] <= 26) ? '@' + c[j] : '?';
+          abAppend(ab, "\x1b[7m", 4);
+          abAppend(ab, &sym, 1);
+          abAppend(ab, "\x1b[m", 3);
+          if (current_color != -1) {
+            char buf[16];
+            int clen = snprintf(buf, sizeof(buf), "\x1b[%dm", current_color);
+            abAppend(ab, buf, clen);
+          }
+        } else if (hl[j] == HL_NORMAL) {
           if (current_color != -1) {
             abAppend(ab, "\x1b[39m", 5);
             current_color = -1;