diff --git a/stix/kernel/Stix.st b/stix/kernel/Stix.st
index 6c6a852..bc0a5fa 100644
--- a/stix/kernel/Stix.st
+++ b/stix/kernel/Stix.st
@@ -258,6 +258,11 @@
 	#dcl owner preamble preamble_data_1 preamble_data_2 ntmprs nargs code source.
 }
 
+#class(#pointer) Process(Object)
+{
+	#dcl state.
+}
+
 
 #class FFI(Object)
 {
diff --git a/stix/lib/Makefile.am b/stix/lib/Makefile.am
index ceb7826..dd60648 100644
--- a/stix/lib/Makefile.am
+++ b/stix/lib/Makefile.am
@@ -45,6 +45,7 @@ libstix_la_SOURCES = \
 	obj.c \
 	sym.c \
 	dic.c \
+	proc.c \
 	ignite.c \
 	utf8.c \
 	comp.c \
diff --git a/stix/lib/Makefile.in b/stix/lib/Makefile.in
index 6f85bfa..69680b3 100644
--- a/stix/lib/Makefile.in
+++ b/stix/lib/Makefile.in
@@ -126,8 +126,8 @@ libstix_la_DEPENDENCIES = $(am__DEPENDENCIES_2)
 am_libstix_la_OBJECTS = libstix_la-stix-rbt.lo libstix_la-stix-utl.lo \
 	libstix_la-stix.lo libstix_la-heap.lo libstix_la-gc.lo \
 	libstix_la-obj.lo libstix_la-sym.lo libstix_la-dic.lo \
-	libstix_la-ignite.lo libstix_la-utf8.lo libstix_la-comp.lo \
-	libstix_la-exec.lo libstix_la-debug.lo
+	libstix_la-proc.lo libstix_la-ignite.lo libstix_la-utf8.lo \
+	libstix_la-comp.lo libstix_la-exec.lo libstix_la-debug.lo
 libstix_la_OBJECTS = $(am_libstix_la_OBJECTS)
 libstix_la_LINK = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
 	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
@@ -380,6 +380,7 @@ libstix_la_SOURCES = \
 	obj.c \
 	sym.c \
 	dic.c \
+	proc.c \
 	ignite.c \
 	utf8.c \
 	comp.c \
@@ -595,6 +596,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-heap.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-ignite.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-obj.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-proc.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-stix-rbt.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-stix-utl.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/libstix_la-stix.Plo@am__quote@
@@ -687,6 +689,13 @@ libstix_la-dic.lo: dic.c
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(libstix_la_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o libstix_la-dic.lo `test -f 'dic.c' || echo '$(srcdir)/'`dic.c
 
+libstix_la-proc.lo: proc.c
+@am__fastdepCC_TRUE@	$(AM_V_CC)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(libstix_la_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT libstix_la-proc.lo -MD -MP -MF $(DEPDIR)/libstix_la-proc.Tpo -c -o libstix_la-proc.lo `test -f 'proc.c' || echo '$(srcdir)/'`proc.c
+@am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/libstix_la-proc.Tpo $(DEPDIR)/libstix_la-proc.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	$(AM_V_CC)source='proc.c' object='libstix_la-proc.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(AM_V_CC@am__nodep@)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(libstix_la_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o libstix_la-proc.lo `test -f 'proc.c' || echo '$(srcdir)/'`proc.c
+
 libstix_la-ignite.lo: ignite.c
 @am__fastdepCC_TRUE@	$(AM_V_CC)$(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(libstix_la_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT libstix_la-ignite.lo -MD -MP -MF $(DEPDIR)/libstix_la-ignite.Tpo -c -o libstix_la-ignite.lo `test -f 'ignite.c' || echo '$(srcdir)/'`ignite.c
 @am__fastdepCC_TRUE@	$(AM_V_at)$(am__mv) $(DEPDIR)/libstix_la-ignite.Tpo $(DEPDIR)/libstix_la-ignite.Plo
diff --git a/stix/lib/gc.c b/stix/lib/gc.c
index 1fb1aa8..a35663e 100644
--- a/stix/lib/gc.c
+++ b/stix/lib/gc.c
@@ -284,6 +284,7 @@ void stix_gc (stix_t* stix)
 	stix->_association       = stix_moveoop (stix, stix->_association);
 	stix->_method_context    = stix_moveoop (stix, stix->_method_context);
 	stix->_block_context     = stix_moveoop (stix, stix->_block_context);
+	stix->_process           = stix_moveoop (stix, stix->_process);
 	stix->_true_class        = stix_moveoop (stix, stix->_true_class);
 	stix->_false_class       = stix_moveoop (stix, stix->_false_class);
 	stix->_character         = stix_moveoop (stix, stix->_character);
diff --git a/stix/lib/ignite.c b/stix/lib/ignite.c
index 553f7a5..844498e 100644
--- a/stix/lib/ignite.c
+++ b/stix/lib/ignite.c
@@ -134,6 +134,7 @@ static int ignite_1 (stix_t* stix)
 
 	stix->_method_context    = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_CONTEXT_NAMED_INSTVARS, 1, STIX_OBJ_TYPE_OOP));
 	stix->_block_context     = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_CONTEXT_NAMED_INSTVARS, 1, STIX_OBJ_TYPE_OOP));
+	stix->_process           = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(STIX_PROCESS_NAMED_INSTVARS, 1, STIX_OBJ_TYPE_OOP));
 	stix->_true_class        = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(0, 0, STIX_OBJ_TYPE_OOP));
 	stix->_false_class       = alloc_kernel_class (stix, 0, STIX_CLASS_SPEC_MAKE(0, 0, STIX_OBJ_TYPE_OOP));
 	/* TOOD: what is a proper spec for Character and SmallInteger?
@@ -151,7 +152,7 @@ static int ignite_1 (stix_t* stix)
 	    !stix->_namespace         || !stix->_pool_dictionary   ||
 	    !stix->_method_dictionary || !stix->_method            || !stix->_association ||
 
-	    !stix->_method_context    || !stix->_block_context     ||
+	    !stix->_method_context    || !stix->_block_context     || !stix->_process ||
 	    !stix->_true_class        || !stix->_false_class       || 
 	    !stix->_character         || !stix->_small_integer) return -1;
 
@@ -223,6 +224,7 @@ static int ignite_3 (stix_t* stix)
 
 		{ 13, { 'M','e','t','h','o','d','C','o','n','t','e','x','t'              } },
 		{ 12, { 'B','l','o','c','k','C','o','n','t','e','x','t'                  } },
+		{  7, { 'P','r','o','c','e','s','s'                                      } },
 		{  4, { 'T','r','u','e'                                                  } },
 		{  5, { 'F','a','l','s','e'                                              } },
 		{  9, { 'C','h','a','r','a','c','t','e','r'                              } },
diff --git a/stix/lib/proc.c b/stix/lib/proc.c
new file mode 100644
index 0000000..752fc5b
--- /dev/null
+++ b/stix/lib/proc.c
@@ -0,0 +1,41 @@
+/*
+ * $Id$
+ *
+    Copyright (c) 2014-2015 Chung, Hyung-Hwan. All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+    NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include "stix-prv.h"
+
+
+stix_oop_process_t stix_makeproc (stix_t* stix)
+{
+	stix_oop_process_t proc;
+
+	proc = (stix_oop_process_t)stix_instantiate (stix, stix->_process, STIX_NULL, stix->option.dfl_procstk_size);
+	if (!proc) return STIX_NULL;
+
+	proc->state = STIX_OOP_FROM_SMINT(0);
+	STIX_ASSERT (STIX_OBJ_GET_SIZE(proc) == STIX_PROCESS_NAMED_INSTVARS + stix->option.dfl_procstk_size);
+	return proc;
+}
diff --git a/stix/lib/stix-prv.h b/stix/lib/stix-prv.h
index 133cde2..cf27249 100644
--- a/stix/lib/stix-prv.h
+++ b/stix/lib/stix-prv.h
@@ -986,6 +986,13 @@ stix_oop_set_t stix_makedic (
 	stix_oow_t size
 );
 
+/* ========================================================================= */
+/* proc.c                                                                    */
+/* ========================================================================= */
+stix_oop_process_t stix_makeproc (
+	stix_t* stix
+);
+
 /* ========================================================================= */
 /* utf8.c                                                                    */
 /* ========================================================================= */
diff --git a/stix/lib/stix.c b/stix/lib/stix.c
index c6ce4e2..7d881d4 100644
--- a/stix/lib/stix.c
+++ b/stix/lib/stix.c
@@ -135,6 +135,10 @@ int stix_setoption (stix_t* stix, stix_option_t id, const void* value)
 		case STIX_SYSDIC_SIZE:
 			stix->option.dfl_sysdic_size = *(stix_oow_t*)value;
 			return 0;
+
+		case STIX_PROCSTK_SIZE:
+			stix->option.dfl_procstk_size = *(stix_oow_t*)value;
+			return 0;
 	}
 
 	stix->errnum = STIX_EINVAL;
@@ -151,9 +155,15 @@ int stix_getoption (stix_t* stix, stix_option_t id, void* value)
 
 		case STIX_SYMTAB_SIZE:
 			*(stix_oow_t*)value = stix->option.dfl_symtab_size;
+			return 0;
 
 		case STIX_SYSDIC_SIZE:
 			*(stix_oow_t*)value = stix->option.dfl_sysdic_size;
+			return 0;
+
+		case STIX_PROCSTK_SIZE:
+			*(stix_oow_t*)value = stix->option.dfl_procstk_size;
+			return 0;
 	};
 
 	stix->errnum = STIX_EINVAL;
diff --git a/stix/lib/stix.h b/stix/lib/stix.h
index 985b723..1138bb3 100644
--- a/stix/lib/stix.h
+++ b/stix/lib/stix.h
@@ -61,8 +61,9 @@ typedef enum stix_errnum_t stix_errnum_t;
 enum stix_option_t
 {
 	STIX_TRAIT,
-	STIX_SYMTAB_SIZE, /* default system table size */
-	STIX_SYSDIC_SIZE  /* default system dictionary size */
+	STIX_SYMTAB_SIZE,  /* default system table size */
+	STIX_SYSDIC_SIZE,  /* default system dictionary size */
+	STIX_PROCSTK_SIZE  /* default process stack size */
 };
 typedef enum stix_option_t stix_option_t;
 
@@ -466,6 +467,20 @@ struct stix_context_t
 	stix_oop_t         slot[1]; /* stack */
 };
 
+
+#define STIX_PROCESS_NAMED_INSTVARS 1
+typedef struct stix_process_t stix_process_t;
+typedef struct stix_process_t* stix_oop_process_t;
+struct stix_process_t
+{
+	STIX_OBJ_HEADER;
+	stix_oop_t  state;
+
+	/* == variable indexed part == */
+	stix_oop_t slot[1]; /* process stack */
+};
+
+
 /**
  * The STIX_CLASSOF() macro return the class of an object including a numeric
  * object encoded into a pointer.
@@ -588,6 +603,7 @@ struct stix_t
 		int trait;
 		stix_oow_t dfl_symtab_size;
 		stix_oow_t dfl_sysdic_size;
+		stix_oow_t dfl_procstk_size; 
 	} option;
 
 	stix_vmprim_t vmprim;
@@ -627,6 +643,7 @@ struct stix_t
 
 	stix_oop_t _method_context; /* MethodContext */
 	stix_oop_t _block_context; /* BlockContext */
+	stix_oop_t _process; /* Process */
 	stix_oop_t _true_class; /* True */
 	stix_oop_t _false_class; /* False */
 	stix_oop_t _character; /* Character */