diff --git a/debugger/src/datasources.js b/debugger/src/datasources.js
index 13843842c..f88230fcd 100644
--- a/debugger/src/datasources.js
+++ b/debugger/src/datasources.js
@@ -64,6 +64,7 @@ module.service('DataSource', function($q) {
 
     this.cache_ = {
       modules: {},
+      moduleFunctionLists: {},
       functions: {}
     };
   };
@@ -104,10 +105,29 @@ module.service('DataSource', function($q) {
   };
 
   DataSource.prototype.getFunctionList = function(moduleName) {
-    return this.issue({
+    var d = $q.defer();
+    var cached = this.cache_.moduleFunctionLists[moduleName];
+    this.issue({
       command: 'cpu.get_function_list',
-      module: moduleName
-    });
+      module: moduleName,
+      since: cached ? cached.version : 0
+    }).then((function(result) {
+      if (cached) {
+        cached.version = result.version;
+        for (var n = 0; n < result.list.length; n++) {
+          cached.list.push(result.list[n]);
+        }
+      } else {
+        cached = this.cache_.moduleFunctionLists[moduleName] = {
+          version: result.version,
+          list: result.list
+        };
+      }
+      d.resolve(cached.list);
+    }).bind(this), (function(e) {
+      d.reject(e);
+    }).bind(this));
+    return d.promise;
   };
 
   DataSource.prototype.getFunction = function(address) {
diff --git a/src/alloy/runtime/module.cc b/src/alloy/runtime/module.cc
index 4259eb829..cdc00bce1 100644
--- a/src/alloy/runtime/module.cc
+++ b/src/alloy/runtime/module.cc
@@ -97,6 +97,7 @@ SymbolInfo::Status Module::DeclareSymbol(
       break;
     }
     map_[address] = symbol_info;
+    list_.push_back(symbol_info);
     status = SymbolInfo::STATUS_NEW;
   }
   UnlockMutex(lock_);
@@ -160,10 +161,25 @@ SymbolInfo::Status Module::DefineVariable(VariableInfo* symbol_info) {
 
 void Module::ForEachFunction(std::function<void (FunctionInfo*)> callback) {
   LockMutex(lock_);
-  for (SymbolMap::iterator it = map_.begin();
-       it != map_.end(); ++it) {
-    if (it->second->type() == SymbolInfo::TYPE_FUNCTION) {
-      FunctionInfo* info = (FunctionInfo*)it->second;
+  for (auto it = list_.begin(); it != list_.end(); ++it) {
+    SymbolInfo* symbol_info = *it;
+    if (symbol_info->type() == SymbolInfo::TYPE_FUNCTION) {
+      FunctionInfo* info = (FunctionInfo*)symbol_info;
+      callback(info);
+    }
+  }
+  UnlockMutex(lock_);
+}
+
+void Module::ForEachFunction(size_t since, size_t& version,
+                             std::function<void (FunctionInfo*)> callback) {
+  LockMutex(lock_);
+  size_t count = list_.size();
+  version = count;
+  for (size_t n = since; n < count; n++) {
+    SymbolInfo* symbol_info = list_[n];
+    if (symbol_info->type() == SymbolInfo::TYPE_FUNCTION) {
+      FunctionInfo* info = (FunctionInfo*)symbol_info;
       callback(info);
     }
   }
diff --git a/src/alloy/runtime/module.h b/src/alloy/runtime/module.h
index bb86f0dc2..005e325a1 100644
--- a/src/alloy/runtime/module.h
+++ b/src/alloy/runtime/module.h
@@ -45,6 +45,8 @@ public:
   SymbolInfo::Status DefineVariable(VariableInfo* symbol_info);
 
   void ForEachFunction(std::function<void (FunctionInfo*)> callback);
+  void ForEachFunction(size_t since, size_t& version,
+                       std::function<void (FunctionInfo*)> callback);
 
   int ReadMap(const char* file_name);
 
@@ -62,6 +64,8 @@ private:
   Mutex* lock_;
   typedef std::tr1::unordered_map<uint64_t, SymbolInfo*> SymbolMap;
   SymbolMap map_;
+  typedef std::vector<SymbolInfo*> SymbolList;
+  SymbolList list_;
 };
 
 
diff --git a/src/xenia/cpu/processor.cc b/src/xenia/cpu/processor.cc
index 91bbc7c50..05ee02b43 100644
--- a/src/xenia/cpu/processor.cc
+++ b/src/xenia/cpu/processor.cc
@@ -225,6 +225,32 @@ void Processor::OnDebugClientDisconnected(uint32_t client_id) {
   runtime_->debugger()->ResumeAllThreads(true);
 }
 
+json_t* json_object_set_string_new(
+    json_t* object, const char* key, const char* value) {
+  json_t* value_json = json_string(value);
+  json_object_set_new(object, key, value_json);
+  return value_json;
+}
+
+json_t* json_object_set_string_format_new(
+    json_t* object, const char* key, const char* format, ...) {
+  char buffer[1024];
+  va_list args;
+  va_start(args, format);
+  xevsnprintfa(buffer, XECOUNT(buffer), format, args);
+  va_end(args);
+  json_t* value_json = json_string(buffer);
+  json_object_set_new(object, key, value_json);
+  return value_json;
+}
+
+json_t* json_object_set_integer_new(
+    json_t* object, const char* key, json_int_t value) {
+  json_t* value_json = json_integer(value);
+  json_object_set_new(object, key, value_json);
+  return value_json;
+}
+
 json_t* Processor::OnDebugRequest(
     uint32_t client_id, const char* command, json_t* request,
     bool& succeeded) {
@@ -240,8 +266,7 @@ json_t* Processor::OnDebugRequest(
     for (auto it = modules.begin(); it != modules.end(); ++it) {
       XexModule* module = (XexModule*)(*it);
       json_t* module_json = json_object();
-      json_t* module_name_json = json_string(module->name());
-      json_object_set_new(module_json, "name", module_name_json);
+      json_object_set_string_new(module_json, "name", module->name());
       json_array_append_new(list, module_json);
     }
     return list;
@@ -270,8 +295,16 @@ json_t* Processor::OnDebugRequest(
       succeeded = false;
       return json_string("Module not found");
     }
+    json_t* since_json = json_object_get(request, "since");
+    if (since_json && !json_is_number(since_json)) {
+      succeeded = false;
+      return json_string("Version since is an invalid type");
+    }
+    size_t since = since_json ?
+        (size_t)json_number_value(since_json) : 0;
     json_t* list = json_array();
-    module->ForEachFunction([&](FunctionInfo* info) {
+    size_t version = 0;
+    module->ForEachFunction(since, version, [&](FunctionInfo* info) {
       json_t* fn_json = json_object();
       const char* name = info->name();
       char name_buffer[32];
@@ -280,15 +313,15 @@ json_t* Processor::OnDebugRequest(
                     info->address());
         name = name_buffer;
       }
-      json_t* name_json = json_string(name);
-      json_object_set_new(fn_json, "name", name_json);
-      json_t* address_json = json_integer(info->address());
-      json_object_set_new(fn_json, "address", address_json);
-      json_t* link_status_json = json_integer(info->status());
-      json_object_set_new(fn_json, "linkStatus", link_status_json);
+      json_object_set_string_new(fn_json, "name", name);
+      json_object_set_integer_new(fn_json, "address", info->address());
+      json_object_set_integer_new(fn_json, "linkStatus", info->status());
       json_array_append_new(list, fn_json);
     });
-    return list;
+    json_t* result = json_object();
+    json_object_set_integer_new(result, "version", version);
+    json_object_set_new(result, "list", list);
+    return result;
   } else if (xestrcmpa(command, "get_function") == 0) {
     json_t* address_json = json_object_get(request, "address");
     if (!address_json || !json_is_number(address_json)) {
@@ -397,32 +430,6 @@ json_t* Processor::OnDebugRequest(
   }
 }
 
-json_t* json_object_set_string_new(
-    json_t* object, const char* key, const char* value) {
-  json_t* value_json = json_string(value);
-  json_object_set_new(object, key, value_json);
-  return value_json;
-}
-
-json_t* json_object_set_string_format_new(
-    json_t* object, const char* key, const char* format, ...) {
-  char buffer[1024];
-  va_list args;
-  va_start(args, format);
-  xevsnprintfa(buffer, XECOUNT(buffer), format, args);
-  va_end(args);
-  json_t* value_json = json_string(buffer);
-  json_object_set_new(object, key, value_json);
-  return value_json;
-}
-
-json_t* json_object_set_integer_new(
-    json_t* object, const char* key, json_int_t value) {
-  json_t* value_json = json_integer(value);
-  json_object_set_new(object, key, value_json);
-  return value_json;
-}
-
 json_t* Processor::DumpModule(XexModule* module, bool& succeeded) {
   auto xex = module->xex();
   auto header = xe_xex2_get_header(xex);