diff --git a/example-project/languages/perl-lang.pl b/example-project/languages/perl-lang.pl
new file mode 100644
index 0000000..2bdfbe5
--- /dev/null
+++ b/example-project/languages/perl-lang.pl
@@ -0,0 +1,7 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+# cc: main function.
+print "Hello, World!\n";
diff --git a/src/server/code-parse/language/index.js b/src/server/code-parse/language/index.js
index cefa0c4..1c20aa5 100644
--- a/src/server/code-parse/language/index.js
+++ b/src/server/code-parse/language/index.js
@@ -12,6 +12,7 @@ const LANGUAGES = [
   'javascript',
   'kotlin',
   'ocaml',
+  'perl',
   'php',
   'python',
   'ruby',
diff --git a/src/server/code-parse/language/perl/codecrumbs.js b/src/server/code-parse/language/perl/codecrumbs.js
new file mode 100644
index 0000000..898206a
--- /dev/null
+++ b/src/server/code-parse/language/perl/codecrumbs.js
@@ -0,0 +1,9 @@
+const { setupGetCrumbs, setupGetCommentsFromCode } = require('../default/codecrumbs');
+
+const PERL_COMMENT_REGEX = /^([^#]*)#(.*)$/;
+const getCrumbs = setupGetCrumbs(setupGetCommentsFromCode(PERL_COMMENT_REGEX));
+
+// replace with own implementation if needed
+module.exports = {
+  getCrumbs
+};
diff --git a/src/server/code-parse/language/perl/dependencies.js b/src/server/code-parse/language/perl/dependencies.js
new file mode 100644
index 0000000..202c0a2
--- /dev/null
+++ b/src/server/code-parse/language/perl/dependencies.js
@@ -0,0 +1,7 @@
+const defaultDependencies = require('../default/dependencies');
+
+// replace with own implementation if needed
+module.exports = {
+  getImports: defaultDependencies.getImports,
+  getDependencies: defaultDependencies.getDependencies
+};
diff --git a/src/server/code-parse/language/perl/extensions.js b/src/server/code-parse/language/perl/extensions.js
new file mode 100644
index 0000000..fdd6b29
--- /dev/null
+++ b/src/server/code-parse/language/perl/extensions.js
@@ -0,0 +1 @@
+module.exports = /\.(pl|al|cgi|fcgi|perl|ph|plx|pm|psgi|t|6pl|6pm|nqp|p6|p6l|p6m|pl|pl6|pm|pm6)$/;
diff --git a/src/server/mediator.js b/src/server/mediator.js
index 9c49fbe..cdb24fb 100644
--- a/src/server/mediator.js
+++ b/src/server/mediator.js
@@ -5,6 +5,10 @@ const { SOCKET_MSG_MAX_SIZE } = require('./config');
 const logger = require('./utils/logger');
 const { SOCKET_MESSAGE_TYPE } = require('./shared-constants');
 
+const connectedJSON = JSON.stringify({
+  type: SOCKET_MESSAGE_TYPE.CLIENT_CONNECTED
+})
+
 // instances should run on many ports but then send data to mediator and mediator to client
 const run = ({ port, clientPort }) => {
   const httpServer = http.createServer();
@@ -29,22 +33,10 @@ const run = ({ port, clientPort }) => {
     if (isClient) {
       clientInstance = connection;
       logger.info('> browser client connected');
-      sendToSourceWatchers(
-        JSON.stringify({
-          type: SOCKET_MESSAGE_TYPE.CLIENT_CONNECTED
-        })
-      );
+      sendToSourceWatchers(connectedJSON);
     } else {
       sourceWatcherInstances.push(connection);
-
-      // if client already there just init watcher
-      if (clientInstance) {
-        connection.sendUTF(
-          JSON.stringify({
-            type: SOCKET_MESSAGE_TYPE.CLIENT_CONNECTED
-          })
-        );
-      }
+      initWatcherIfClientExist(client, connection)
     }
 
     connection.on('message', ({ utf8Data }) => {
@@ -61,6 +53,12 @@ const run = ({ port, clientPort }) => {
   });
 };
 
+function initWatcherIfClientExist (client, connection) {
+  if (client) {
+    connection.sendUTF(connectedJSON)
+  }
+}
+
 module.exports = {
   run
 };
diff --git a/src/server/project-source/file-system.js b/src/server/project-source/file-system.js
index 8fd7dfd..01578d1 100644
--- a/src/server/project-source/file-system.js
+++ b/src/server/project-source/file-system.js
@@ -3,7 +3,11 @@ const directoryTree = require('directory-tree');
 const { traversal: treeTraversal } = require('../utils/tree');
 const { DIR_NODE_TYPE } = require('../shared-constants');
 
-const getProjectFiles = (projectDir, config = { extensions: /(.*?)/ }) => {
+const DEFAULT_EXTENSION_REGEX = require('../code-parse/language/default/extensions')
+const DEFAULT_CONFIG = { extensions: DEFAULT_EXTENSION_REGEX }
+const NO_FILES_ERROR = 'There is not files found. Please check source dir and entry point configs.';
+
+const getProjectFiles = (projectDir, config = DEFAULT_CONFIG) => {
   const filesMap = {};
   const foldersMap = {};
 
@@ -12,7 +16,7 @@ const getProjectFiles = (projectDir, config = { extensions: /(.*?)/ }) => {
   });
 
   if (!Object.keys(filesMap).length) {
-    throw new Error('There is not files found. Please check source dir and entry point configs.');
+    throw new Error(NO_FILES_ERROR);
   }
 
   treeTraversal(sourceTree, node => {