diff --git a/doc/grammar.bnf b/doc/grammar.bnf
index a7e193b..044280f 100644
--- a/doc/grammar.bnf
+++ b/doc/grammar.bnf
@@ -3,4 +3,6 @@ EXPR ::=
   bool
 | ident
 | VARDECL
+| FUNCALL
 VARDECL ::= opar decl ident EXPR cpar
+FUNCALL ::= opar ident EXPR* cpar
diff --git a/lib/core.cpp b/lib/core.cpp
new file mode 100644
index 0000000..374fcb4
--- /dev/null
+++ b/lib/core.cpp
@@ -0,0 +1,19 @@
+#include "../src/Loader.hpp"
+
+extern "C" void lib(grino::Loader& loader)
+{
+  loader.add_native("dump", [](auto args){
+    std::string sep;
+    std::stringstream ss;
+
+    for (auto arg: args)
+      {
+        ss << sep << arg->string();
+        sep = " ";
+      }
+
+    std::cout << ss.str() << std::endl;
+
+    return grino::Value::make_nil();
+  });
+}
diff --git a/meson.build b/meson.build
index 8a8e406..9641ad9 100644
--- a/meson.build
+++ b/meson.build
@@ -6,8 +6,11 @@ project('grino',
           'cpp_std=c++17'
         ])
 
+grino_libdir = get_option('prefix') / get_option('libdir') / 'grino'
+
 conf = configuration_data()
 conf.set('version', meson.project_version())
+conf.set('libdir', grino_libdir)
 
 configure_file(input: 'src/config.in.hpp',
                output: 'config.hpp',
@@ -24,11 +27,23 @@ grino_src = static_library('grino',
                              'src/Program.cpp',
                              'src/VM.cpp',
                              'src/Value.cpp',
+                             'src/Function.cpp',
                              'src/SymTable.cpp',
+                             'src/Loader.cpp',
                            ])
 
 grino_dep = declare_dependency(link_with: grino_src)
 
+shared_library('grino_core',
+               sources: [
+                 'lib/core.cpp'
+               ],
+               dependencies: [
+                 grino_dep
+               ],
+               install: true,
+               install_dir: grino_libdir)
+
 executable('grino',
            sources: [
              'src/main.cpp'
diff --git a/src/Compiler.cpp b/src/Compiler.cpp
index 74beece..e5f414c 100644
--- a/src/Compiler.cpp
+++ b/src/Compiler.cpp
@@ -28,6 +28,16 @@ namespace grino
           }
       } break;
 
+      case NODE_FUNCALL: {
+
+        for (size_t i=0; i<node->size(); i++)
+          {
+            compile(node->child(i).lock(), program);
+          }
+
+        program.push_instr(OPCODE_CALL, node->size() - 1);
+      } break;
+
       case NODE_BOOL: {
         std::string repr = node->repr();
         auto value = Value::make_bool(repr == "true");
@@ -58,7 +68,14 @@ namespace grino
             m_logger.log<compile_error>(LOG_ERROR, node->loc(), ss.str());
           }
 
-        program.push_instr(OPCODE_LOAD_LOCAL, entry->addr);
+        if (entry->is_object)
+          {
+            program.push_instr(OPCODE_LOAD_OBJ, entry->addr);
+          }
+        else
+          {
+            program.push_instr(OPCODE_LOAD_LOCAL, entry->addr);
+          }
       } break;
 
       default:
diff --git a/src/Function.cpp b/src/Function.cpp
new file mode 100644
index 0000000..02af6dc
--- /dev/null
+++ b/src/Function.cpp
@@ -0,0 +1,20 @@
+#include "Function.hpp"
+#include "Value.hpp"
+
+namespace grino
+{
+  /*explicit*/ Function::Function(native_t native)
+    : m_native { native }
+  {
+  }
+
+  /*virtual*/ Function::~Function()
+  {
+  }
+
+  value_t Function::call(args_t args)
+  {
+    assert(m_native);
+    return m_native(args);
+  }
+}
diff --git a/src/Function.hpp b/src/Function.hpp
new file mode 100644
index 0000000..1ac67ae
--- /dev/null
+++ b/src/Function.hpp
@@ -0,0 +1,27 @@
+#ifndef grino_FUNCTION_HPP
+#define grino_FUNCTION_HPP
+
+#include "commons.hpp"
+
+namespace grino
+{
+  class Value;
+
+  using value_t = std::shared_ptr<Value>;
+  using args_t = std::vector<value_t>;
+  using native_t = std::function<value_t(args_t)>;
+
+  class Function
+  {
+  public:
+    explicit Function(native_t native);
+    virtual ~Function();
+
+    value_t call(args_t args);
+
+  private:
+    native_t m_native;
+  };
+}
+
+#endif
diff --git a/src/Loader.cpp b/src/Loader.cpp
new file mode 100644
index 0000000..1bb1555
--- /dev/null
+++ b/src/Loader.cpp
@@ -0,0 +1,45 @@
+#include "Loader.hpp"
+#include "Function.hpp"
+#include "src/config.in.hpp"
+#include <dlfcn.h>
+
+namespace grino
+{
+  /*explicit*/ Loader::Loader(VM& vm, SymTable& sym_table)
+    : m_vm { vm }
+    , m_sym_table { sym_table }
+  {
+  }
+
+  /*virtual*/ Loader::~Loader()
+  {
+  }
+
+  void Loader::load_libraries()
+  {
+    for (auto entry: std::filesystem::directory_iterator(GRINO_LIBDIR))
+      {
+        if (entry.path().has_extension()
+            && entry.path().extension() == ".so")
+          {
+            load_library(entry.path());
+          }
+      }
+  }
+
+  void Loader::load_library(std::filesystem::path path)
+  {
+    void* handle = dlopen(path.string().c_str(), RTLD_NOW);
+    typedef void(*libfun)(Loader&);
+    libfun f = (libfun) dlsym(handle, "lib");
+
+    f(*this);
+  }
+
+  void Loader::add_native(std::string const& name, native_t native)
+  {
+    size_t addr = m_vm.heap_size();
+    m_vm.set_heap(addr, grino::Value::make_native_function(native));
+    m_sym_table.declare_object(grino::Loc {"???", 1}, name, addr);
+  }
+}
diff --git a/src/Loader.hpp b/src/Loader.hpp
new file mode 100644
index 0000000..4f99d94
--- /dev/null
+++ b/src/Loader.hpp
@@ -0,0 +1,26 @@
+#ifndef grino_LOADER_HPP
+#define grino_LOADER_HPP
+
+#include "commons.hpp"
+#include "VM.hpp"
+#include "SymTable.hpp"
+
+namespace grino
+{
+  class Loader
+  {
+  public:
+    explicit Loader(VM& vm, SymTable& sym_table);
+    virtual ~Loader();
+
+    void load_libraries();
+    void load_library(std::filesystem::path path);
+    void add_native(std::string const& name, native_t native);
+
+  private:
+    VM& m_vm;
+    SymTable& m_sym_table;
+  };
+}
+
+#endif
diff --git a/src/Node.hpp b/src/Node.hpp
index 7b7fb52..30d2bfa 100644
--- a/src/Node.hpp
+++ b/src/Node.hpp
@@ -8,6 +8,7 @@
   G(NODE_MODULE),                               \
     G(NODE_BOOL),                               \
     G(NODE_VARDECL),                            \
+    G(NODE_FUNCALL),                            \
     G(NODE_IDENT),                              \
     G(NODE_OPAR),                               \
     G(NODE_CPAR),                               \
diff --git a/src/Parser.cpp b/src/Parser.cpp
index 68d81a2..33600a4 100644
--- a/src/Parser.cpp
+++ b/src/Parser.cpp
@@ -117,7 +117,12 @@ namespace grino
 
   std::shared_ptr<Node> Parser::parse_expr()
   {
-    if (type_is(NODE_OPAR))
+    if (type_is({NODE_OPAR, NODE_IDENT}))
+      {
+        return parse_funcall();
+      }
+
+    if (type_is({NODE_OPAR, NODE_DECL}))
       {
         return parse_vardecl();
       }
@@ -151,4 +156,21 @@ namespace grino
 
     return node;
   }
+
+  std::shared_ptr<Node> Parser::parse_funcall()
+  {
+    consume(NODE_OPAR);
+
+    auto node = make_node(NODE_FUNCALL);
+    node->add_child(consume(NODE_IDENT));
+
+    while (!type_is(NODE_CPAR))
+      {
+        node->add_child(parse_expr());
+      }
+
+    consume(NODE_CPAR);
+
+    return node;
+  }
 }
diff --git a/src/Parser.hpp b/src/Parser.hpp
index fe89d0a..54891a5 100644
--- a/src/Parser.hpp
+++ b/src/Parser.hpp
@@ -35,6 +35,7 @@ namespace grino
     std::shared_ptr<Node> parse_module();
     std::shared_ptr<Node> parse_expr();
     std::shared_ptr<Node> parse_vardecl();
+    std::shared_ptr<Node> parse_funcall();
   };
 }
 
diff --git a/src/SymTable.cpp b/src/SymTable.cpp
index a220e7c..9d0df11 100644
--- a/src/SymTable.cpp
+++ b/src/SymTable.cpp
@@ -23,11 +23,19 @@ namespace grino
     SymEntry entry;
     entry.addr = addr;
     entry.name = name;
-    entry.is_global = false;
+    entry.is_object = false;
 
     m_entries.push_back(entry);
   }
 
+  void SymTable::declare_object(Loc const& loc,
+                                std::string const& name,
+                                size_t addr)
+  {
+    declare(loc, name, addr);
+    m_entries.back().is_object = true;
+  }
+
   std::optional<SymEntry> SymTable::find(std::string const& name)
   {
     for (size_t i=0; i<m_entries.size(); i++)
diff --git a/src/SymTable.hpp b/src/SymTable.hpp
index 5a7fdd9..afbeb29 100644
--- a/src/SymTable.hpp
+++ b/src/SymTable.hpp
@@ -8,8 +8,8 @@ namespace grino
 {
   struct SymEntry {
     std::string name;
-    bool is_global;
-    size_t addr;
+    bool is_object; /* object are on the heap instead of the stack */
+    size_t addr; /* address on the heap if object, local address otherwise */
   };
 
   GRINO_ERROR(symbolic_error);
@@ -21,6 +21,8 @@ namespace grino
     virtual ~SymTable();
 
     void declare(Loc const& loc, std::string const& name, size_t addr);
+    void declare_object(Loc const& loc, std::string const& name, size_t addr);
+
     std::optional<SymEntry> find(std::string const& name);
 
     std::string string() const;
diff --git a/src/VM.cpp b/src/VM.cpp
index dc76f03..ebb054f 100644
--- a/src/VM.cpp
+++ b/src/VM.cpp
@@ -48,6 +48,34 @@ namespace grino
             m_pc++;
           } break;
 
+          case OPCODE_LOAD_OBJ: {
+            size_t addr = *instr.param;
+            auto ref = Value::make_ref(addr);
+            push(program.push_constant(ref));
+            m_pc++;
+          } break;
+
+          case OPCODE_CALL: {
+            size_t const N = *instr.param;
+
+            std::vector<std::shared_ptr<Value>> args;
+
+            for (size_t i=0; i<N; i++)
+              {
+                args.insert(std::begin(args), program.constant(pop()));
+              }
+
+            size_t ref = program.constant(pop())->as_ref();
+            auto fun = heap(ref)->as_function();
+
+            auto ret = fun->call(args);
+
+            push(program.push_constant(ret));
+
+            m_pc++;
+
+          } break;
+
           default:
             std::cerr << "cannot execute unknown opcode "
                       << OpcodeTypeStr[instr.opcode]
@@ -69,6 +97,29 @@ namespace grino
     return ss.str();
   }
 
+
+  std::shared_ptr<Value> VM::local(size_t addr) const
+  {
+    return m_frames.back().locals.at(addr);
+  }
+
+  void VM::set_local(size_t addr,
+                     std::shared_ptr<Value> value)
+  {
+    m_frames.back().locals[addr] = value;
+  }
+
+  std::shared_ptr<Value> VM::heap(size_t addr) const
+  {
+    return m_heap.at(addr);
+  }
+
+  void VM::set_heap(size_t addr,
+                    std::shared_ptr<Value> value)
+  {
+    m_heap[addr] = value;
+  }
+
   void VM::push(size_t addr)
   {
     if (m_sp >= STACK_SIZE)
@@ -97,16 +148,4 @@ namespace grino
     size_t addr = m_stack[m_sp - 1];
     return addr;
   }
-
-  std::shared_ptr<Value> VM::local(size_t addr) const
-  {
-    return m_frames.back().locals.at(addr);
-  }
-
-  void VM::set_local(size_t addr,
-                     std::shared_ptr<Value> value)
-  {
-    m_frames.back().locals[addr] = value;
-  }
-
 }
diff --git a/src/VM.hpp b/src/VM.hpp
index 86b9ca8..49845da 100644
--- a/src/VM.hpp
+++ b/src/VM.hpp
@@ -21,12 +21,23 @@ namespace grino
     explicit VM(Logger& logger);
     virtual ~VM();
 
+    size_t heap_size() const { return m_heap.size(); }
+
     void run(Program& program);
 
     std::string string() const;
+
+    std::shared_ptr<Value> local(size_t addr) const;
+    void set_local(size_t addr,
+                   std::shared_ptr<Value> value);
+
+    std::shared_ptr<Value> heap(size_t addr) const;
+    void set_heap(size_t addr,
+                  std::shared_ptr<Value> value);
   private:
     Logger& m_logger;
     std::array<size_t, STACK_SIZE> m_stack;
+    std::unordered_map<size_t, std::shared_ptr<Value>> m_heap;
     std::vector<Frame> m_frames;
 
     size_t m_sp; /* stack pointer */
@@ -36,9 +47,8 @@ namespace grino
     void push(size_t addr);
     size_t pop();
     size_t top();
-    std::shared_ptr<Value> local(size_t addr) const;
-    void set_local(size_t addr,
-                   std::shared_ptr<Value> value);
+
+
   };
 }
 
diff --git a/src/Value.cpp b/src/Value.cpp
index 4061f63..fa34411 100644
--- a/src/Value.cpp
+++ b/src/Value.cpp
@@ -17,13 +17,31 @@ namespace grino
     return value;
   }
 
+  /*static*/
+  std::shared_ptr<Value> Value::make_native_function(native_t val)
+  {
+    auto value = std::make_shared<Value>();
+    value->m_type = TYPE_FUNCTION;
+    value->m_function_val = std::make_shared<Function>(val);
+    return value;
+  }
+
+  /*static*/ std::shared_ptr<Value> Value::make_ref(size_t val)
+  {
+    auto value = std::make_shared<Value>();
+    value->m_type = TYPE_REF;
+    value->m_ref_val = val;
+    return value;
+  }
+
   std::string Value::string() const
   {
     switch (m_type)
       {
       case TYPE_NIL: return "<nil>";
       case TYPE_BOOL: return *m_bool_val ? "true" : "false";
-
+      case TYPE_FUNCTION: return "<function>";
+      case TYPE_REF: return "&" + std::to_string(*m_ref_val);
       default:
         std::cerr << "cannot stringify value "
                   << TypeTypeStr[m_type] << std::endl;
@@ -39,6 +57,7 @@ namespace grino
       {
       case TYPE_NIL: return true;
       case TYPE_BOOL: return *m_bool_val == *other.m_bool_val;
+      case TYPE_REF: return *m_ref_val == *other.m_ref_val;
 
       default:
         std::cerr << "cannot compare equality with value "
diff --git a/src/Value.hpp b/src/Value.hpp
index 88fe4f2..87bae81 100644
--- a/src/Value.hpp
+++ b/src/Value.hpp
@@ -3,6 +3,7 @@
 
 #include "commons.hpp"
 #include "types.hpp"
+#include "Function.hpp"
 
 namespace grino
 {
@@ -11,12 +12,16 @@ namespace grino
   public:
     static std::shared_ptr<Value> make_nil();
     static std::shared_ptr<Value> make_bool(bool val);
+    static std::shared_ptr<Value> make_native_function(native_t val);
+    static std::shared_ptr<Value> make_ref(size_t val);
 
     explicit Value() = default;
     virtual ~Value() = default;
 
     TypeType type() const { return m_type; }
     bool as_bool() const { return *m_bool_val; }
+    std::shared_ptr<Function> as_function() const { return m_function_val; }
+    size_t as_ref() const { return *m_ref_val; }
 
     std::string string() const;
     bool equals(Value const& other) const;
@@ -24,6 +29,8 @@ namespace grino
   private:
     TypeType m_type = TYPE_NIL;
     std::optional<bool> m_bool_val;
+    std::shared_ptr<Function> m_function_val;
+    std::optional<size_t> m_ref_val;
   };
 }
 
diff --git a/src/config.in.hpp b/src/config.in.hpp
index dcba94a..acfdfe0 100644
--- a/src/config.in.hpp
+++ b/src/config.in.hpp
@@ -1,6 +1,9 @@
 #ifndef grino_CONFIG_IN_HPP
 #define grino_CONFIG_IN_HPP
 
+#include <filesystem>
+
 #define GRINO_VERSION "@version@"
+#define GRINO_LIBDIR std::filesystem::path {"@libdir@"}
 
 #endif
diff --git a/src/main.cpp b/src/main.cpp
index e05604d..09578bd 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -9,6 +9,7 @@
 #include "VM.hpp"
 #include "Logger.hpp"
 #include "src/SymTable.hpp"
+#include "Loader.hpp"
 
 int main(int argc, char** argv)
 {
@@ -74,7 +75,12 @@ int main(int argc, char** argv)
           std::cout << "--- ast ---" << std::endl;
           std::cout << ast->string() << std::endl;
         }
+
       grino::SymTable sym_table {logger};
+      grino::VM vm {logger};
+
+      grino::Loader loader {vm, sym_table};
+      loader.load_libraries();
 
       grino::Compiler compiler {logger, sym_table};
       grino::Program program;
@@ -86,8 +92,6 @@ int main(int argc, char** argv)
           std::cout << program.string() << std::endl;
         }
 
-      grino::VM vm {logger};
-
       vm.run(program);
 
       if (debug_mode)
diff --git a/src/opcodes.hpp b/src/opcodes.hpp
index d20c591..9ad6f2c 100644
--- a/src/opcodes.hpp
+++ b/src/opcodes.hpp
@@ -8,7 +8,11 @@
   G(OPCODE_LOAD_CONST),                         \
     G(OPCODE_POP),                              \
     G(OPCODE_LOAD_LOCAL),                       \
-    G(OPCODE_STORE_LOCAL)
+    G(OPCODE_STORE_LOCAL),                      \
+    G(OPCODE_LOAD_OBJ),                         \
+    G(OPCODE_STORE_OBJ),                        \
+    G(OPCODE_CALL),                             \
+    G(OPCODE_RET),
 
 namespace grino
 {
diff --git a/src/types.hpp b/src/types.hpp
index 0350d8d..d989f6d 100644
--- a/src/types.hpp
+++ b/src/types.hpp
@@ -5,7 +5,9 @@
 
 #define TYPES(G)                                \
   G(TYPE_NIL),                                  \
-    G(TYPE_BOOL)
+    G(TYPE_BOOL),                               \
+    G(TYPE_FUNCTION),                           \
+    G(TYPE_REF)
 
 namespace grino
 {
diff --git a/tests/Parser.cpp b/tests/Parser.cpp
index d0914ed..72ac39e 100644
--- a/tests/Parser.cpp
+++ b/tests/Parser.cpp
@@ -39,3 +39,12 @@ TEST_CASE_METHOD(ParserTest, "Parser_vardecl")
   test_parse("MODULE(VARDECL(IDENT[hello],IDENT[world]))",
              "($ hello world)");
 }
+
+TEST_CASE_METHOD(ParserTest, "Parser_funcall")
+{
+  test_parse("MODULE(FUNCALL(IDENT[hello]))",
+             "(hello)");
+
+  test_parse("MODULE(FUNCALL(IDENT[f],BOOL[false],BOOL[true]))",
+             "(f false true)");
+}