diff --git a/.travis.yml b/.travis.yml
index ae2f155..4498759 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,6 @@
+arch:
+    - amd64
+    - ppc64le
 language: ruby
 install:
   - sudo apt-get install libpcre3 libpcre3-dev libmagic-dev gperf gcc ragel swig
diff --git a/README.md b/README.md
index 5954312..afcfc26 100644
--- a/README.md
+++ b/README.md
@@ -50,10 +50,6 @@
 
 Ohcount does not support Windows.
 
-Ohcount targets Ruby 2.5.0. The ruby dev headers provided by Ubuntu/Fedora
-package managers were found to be missing a *config.h* header file. Installing
-ruby using brew/rbenv/rvm works better for compiling ohcount.
-
 Source Code
 -----------
 
@@ -64,10 +60,26 @@
 Building Ohcount
 ----------------
 
-> Last updated: 2019-01-28
+> Last updated: 2020-02-12
+
+Ohcount targets `Ruby 2.*`. The ruby dev headers provided by Ubuntu/Fedora
+package managers were found to be missing a `config.h` header file. If the
+default ruby and ruby-dev packages do not work, install ruby using
+brew/rbenv/asdf/rvm, which work reliably with ohcount.
 
 You will need ragel 7.0 or higher, bash, gperf, libpcre3-dev, libmagic-dev,
 gcc(version 7.3 or greater) and swig (>=3.0.0).
+For older gcc versions one could try [this fix](https://github.com/blackducksoftware/ohcount/pull/70/commits/c7511b9810a8660a8268a958fee0e365fb9af18f).
+
+```
+$ git clone git://github.com/blackducksoftware/ohcount.git
+$ cd ohcount
+```
+
+For the ruby bindings, there is a dependency for the 'test-unit' gem:
+```
+$ gem install test-unit
+```
 
 #### Ubuntu/Debian
 
@@ -90,11 +102,9 @@
 $ ./build
 ```
 
-For the ruby bindings, there is a dependency for the 'test-unit' gem:
+#### Other Unix systems
 
-```
-$ gem install test-unit
-```
+* If build fails with a missing `ohcount.so` error and any `ruby/x86.../` folder has the file, copy it to `ruby/` folder.
 
 Using Ohcount
 -------------
diff --git a/debian/changelog b/debian/changelog
index ad3f67a..114d0e4 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,10 +1,10 @@
-ohcount (4.0.0-2) UNRELEASED; urgency=medium
+ohcount (4.0.0+git20210223.6654d48-1) UNRELEASED; urgency=medium
 
   * Bump debhelper from old 9 to 12.
   * Set debhelper-compat version in Build-Depends.
   * Set upstream metadata fields: Repository, Repository-Browse.
 
- -- Debian Janitor <janitor@jelmer.uk>  Thu, 21 Nov 2019 03:29:25 +0000
+ -- Debian Janitor <janitor@jelmer.uk>  Fri, 26 Mar 2021 18:27:12 -0000
 
 ohcount (4.0.0-1) unstable; urgency=medium
 
diff --git a/src/hash/extensions.gperf b/src/hash/extensions.gperf
index c264648..b2a31ff 100755
--- a/src/hash/extensions.gperf
+++ b/src/hash/extensions.gperf
@@ -51,6 +51,7 @@
 cu, LANG_CUDA
 cxx, LANG_CPP
 d, LANG_DMD
+dart, LANG_DART
 dat, DISAMBIGUATE("dat")
 def, DISAMBIGUATE("def")
 di, LANG_DMD
@@ -198,6 +199,7 @@
 sci, LANG_SCILAB
 scm, LANG_SCHEME
 sh, LANG_SHELL
+sld, LANG_SCHEME
 sls, LANG_SCHEME
 sps, LANG_SCHEME
 sql, LANG_SQL
diff --git a/src/hash/languages.gperf b/src/hash/languages.gperf
index 7c70f95..2d24947 100755
--- a/src/hash/languages.gperf
+++ b/src/hash/languages.gperf
@@ -32,6 +32,7 @@
 csharp, LANG_CSHARP, "C#", 0
 css, LANG_CSS, "CSS", 1
 cuda, LANG_CUDA, "CUDA", 0
+dart, LANG_DART, "Dart", 0
 dcl, LANG_DCL, "DCL", 0
 dmd, LANG_DMD, "D", 0
 dtx, LANG_TEX_DTX, "DTX for TeX/LaTeX", 1
diff --git a/src/hash/parsers.gperf b/src/hash/parsers.gperf
index 577002c..0dd4b55 100644
--- a/src/hash/parsers.gperf
+++ b/src/hash/parsers.gperf
@@ -25,6 +25,7 @@
 #include "../parsers/css.h"
 #include "../parsers/d.h"
 #include "../parsers/dcl.h"
+#include "../parsers/dart.h"
 #include "../parsers/dylan.h"
 #include "../parsers/ebuild.h"
 #include "../parsers/eiffel.h"
@@ -135,6 +136,7 @@
 csharp, parse_csharp
 css, parse_css
 cuda, parse_cuda
+dart, parse_dart
 dcl, parse_dcl
 dmd, parse_d
 dylan, parse_dylan
diff --git a/src/languages.h b/src/languages.h
index 0df901e..0d7ee7e 100755
--- a/src/languages.h
+++ b/src/languages.h
@@ -34,6 +34,7 @@
 #define LANG_CSHARP "csharp"
 #define LANG_CSS "css"
 #define LANG_CUDA "cuda"
+#define LANG_DART "dart"
 #define LANG_DCL "dcl"
 #define LANG_DMD "dmd"
 #define LANG_DYLAN "dylan"
diff --git a/src/parsers/dart.rl b/src/parsers/dart.rl
new file mode 100755
index 0000000..9669564
--- /dev/null
+++ b/src/parsers/dart.rl
@@ -0,0 +1,118 @@
+/************************* Required for every parser *************************/
+#ifndef OHCOUNT_DART_PARSER_H
+#define OHCOUNT_DART_PARSER_H
+
+#include "../parser_macros.h"
+
+// the name of the language
+const char *DART_LANG = LANG_DART;
+
+// the languages entities
+const char *dart_entities[] = {
+  "space", "comment", "any"
+};
+
+// constants associated with the entities
+enum {
+  DART_SPACE = 0, DART_COMMENT, DART_ANY
+};
+
+/*****************************************************************************/
+
+%%{
+  machine dart;
+  write data;
+  include common "common.rl";
+
+  # Line counting machine
+
+  action dart_ccallback {
+    switch(entity) {
+    case DART_SPACE:
+      ls
+      break;
+    case DART_ANY:
+      code
+      break;
+    case INTERNAL_NL:
+      std_internal_newline(DART_LANG)
+      break;
+    case NEWLINE:
+      std_newline(DART_LANG)
+    }
+  }
+
+  dart_line_comment =
+    '//' @comment (
+      escaped_newline %{ entity = INTERNAL_NL; } %dart_ccallback
+      |
+      ws
+      |
+      (nonnewline - ws) @comment
+    )*;
+  dart_block_comment =
+    '/*' @comment (
+      newline %{ entity = INTERNAL_NL; } %dart_ccallback
+      |
+      ws
+      |
+      (nonnewline - ws) @comment
+    )* :>> '*/';
+  dart_comment = dart_line_comment | dart_block_comment;
+
+  dart_line := |*
+    spaces    ${ entity = DART_SPACE; } => dart_ccallback;
+    dart_comment;
+    newline   ${ entity = NEWLINE; } => dart_ccallback;
+    ^space    ${ entity = DART_ANY;   } => dart_ccallback;
+  *|;
+
+  # Entity machine
+  # TODO: This is a placeholder and most entities are missing.
+
+  action dart_ecallback {
+    callback(DART_LANG, dart_entities[entity], cint(ts), cint(te), userdata);
+  }
+
+  dart_line_comment_entity = '//' (escaped_newline | nonnewline)*;
+  dart_block_comment_entity = '/*' any* :>> '*/';
+  dart_comment_entity = dart_line_comment_entity | dart_block_comment_entity;
+
+  dart_entity := |*
+    space+                 ${ entity = DART_SPACE;      } => dart_ecallback;
+    dart_comment_entity    ${ entity = DART_COMMENT;    } => dart_ecallback;
+    ^space;
+  *|;
+}%%
+
+/************************* Required for every parser *************************/
+
+/* Parses a string buffer with Dart code.
+ *
+ * @param *buffer The string to parse.
+ * @param length The length of the string to parse.
+ * @param count Integer flag specifying whether or not to count lines. If yes,
+ *   uses the Ragel machine optimized for counting. Otherwise uses the Ragel
+ *   machine optimized for returning entity positions.
+ * @param *callback Callback function. If count is set, callback is called for
+ *   every line of code, comment, or blank with 'lcode', 'lcomment', and
+ *   'lblank' respectively. Otherwise callback is called for each entity found.
+ */
+void parse_dart(char *buffer, int length, int count,
+             void (*callback) (const char *lang, const char *entity, int s,
+                               int e, void *udata),
+             void *userdata
+  ) {
+  init
+
+  %% write init;
+  cs = (count) ? dart_en_dart_line : dart_en_dart_entity;
+  %% write exec;
+
+  // if no newline at EOF; callback contents of last line
+  if (count) { process_last_line(DART_LANG) }
+}
+
+#endif
+
+/*****************************************************************************/
\ No newline at end of file
diff --git a/test/detect_files/foo.dart b/test/detect_files/foo.dart
new file mode 100644
index 0000000..0f3009c
--- /dev/null
+++ b/test/detect_files/foo.dart
@@ -0,0 +1,4 @@
+// Example Dart code
+void main() {
+  print("Hello, World!");
+}
\ No newline at end of file
diff --git a/test/expected_dir/foo.dart b/test/expected_dir/foo.dart
new file mode 100644
index 0000000..a8e6a77
--- /dev/null
+++ b/test/expected_dir/foo.dart
@@ -0,0 +1,9 @@
+dart	code	void main() {
+dart	comment	  // Line comment
+dart	blank	
+dart	comment	  /* Block
+dart	comment	     comment */
+dart	blank	
+dart	code	  print("Hello!"); // Code with line comment
+dart	code	  print("World!"); /* Code with block comment */
+dart	code	}
diff --git a/test/src_dir/foo.dart b/test/src_dir/foo.dart
new file mode 100644
index 0000000..c560395
--- /dev/null
+++ b/test/src_dir/foo.dart
@@ -0,0 +1,9 @@
+void main() {
+  // Line comment
+
+  /* Block
+     comment */
+
+  print("Hello!"); // Code with line comment
+  print("World!"); /* Code with block comment */
+}
diff --git a/test/unit/detector_test.h b/test/unit/detector_test.h
index ff544ff..fef3b46 100755
--- a/test/unit/detector_test.h
+++ b/test/unit/detector_test.h
@@ -221,6 +221,10 @@
   ASSERT_DETECT(LANG_BFPP, "foo.bfpp");
 }
 
+void test_detector_dart() {
+  ASSERT_DETECT(LANG_DART, "foo.dart");
+}
+
 void test_detector_emacs_mode() {
 	ASSERT_DETECT(LANG_C, "emacs_mode_c");
 }
@@ -272,6 +276,7 @@
   test_detector_basic();
   test_detector_xml_with_custom_extension();
   test_detector_brainfuck();
+  test_detector_dart();
   test_detector_emacs_mode();
   test_detector_emacs_with_extension();
   test_detector_puppet();
diff --git a/test/unit/parser_test.h b/test/unit/parser_test.h
index 4c9c588..92c489d 100644
--- a/test/unit/parser_test.h
+++ b/test/unit/parser_test.h
@@ -98,6 +98,7 @@
 #include "parsers/test_csharp.h"
 #include "parsers/test_css.h"
 #include "parsers/test_d.h"
+#include "parsers/test_dart.h"
 #include "parsers/test_dcl.h"
 #include "parsers/test_dylan.h"
 #include "parsers/test_ebuild.h"
@@ -288,6 +289,7 @@
   all_cs_aspx_tests();
   all_csharp_tests();
   all_css_tests();
+  all_dart_tests();
   all_dmd_tests();
   all_dcl_tests();
   all_dylan_tests();
diff --git a/test/unit/parsers/test_dart.h b/test/unit/parsers/test_dart.h
new file mode 100644
index 0000000..46275dc
--- /dev/null
+++ b/test/unit/parsers/test_dart.h
@@ -0,0 +1,39 @@
+
+void test_dart_comments() {
+  test_parser_verify_parse(
+    test_parser_sourcefile("dart", " //comment"),
+    "dart", "", "//comment", 0
+  );
+}
+
+void test_dart_empty_comments() {
+  test_parser_verify_parse(
+    test_parser_sourcefile("dart", " //\n"),
+    "dart", "", "//\n", 0
+  );
+}
+
+void test_dart_block_comment() {
+  test_parser_verify_parse(
+    test_parser_sourcefile("dart", "/*comment*/"),
+    "dart", "", "/*comment*/", 0
+  );
+}
+
+void test_dart_comment_entities() {
+  test_parser_verify_entity(
+    test_parser_sourcefile("dart", " //comment"),
+    "comment", "//comment"
+  );
+  test_parser_verify_entity(
+    test_parser_sourcefile("c", " /*comment*/"),
+    "comment", "/*comment*/"
+  );
+}
+
+void all_dart_tests() {
+  test_dart_comments();
+  test_dart_empty_comments();
+  test_dart_block_comment();
+  test_dart_comment_entities();
+}