diff -ru tamarin-central.org/MMgc/manifest.mk tamarin-central/MMgc/manifest.mk
--- tamarin-central.org/MMgc/manifest.mk	2008-04-25 11:16:16.000000000 +0900
+++ tamarin-central/MMgc/manifest.mk	2008-04-25 12:34:11.000000000 +0900
@@ -92,4 +92,12 @@
   $(NULL)
 endif
 
+ifeq (freebsd,$(TARGET_OS))
+MMgc_CXXSRCS := $(MMgc_CXXSRCS) \
+  $(curdir)/GCAllocObjectUnix.cpp \
+  $(curdir)/GCDebugUnix.cpp \
+  $(curdir)/GCHeapUnix.cpp \
+  $(NULL)
+endif
+
 $(curdir)/GCDebugMac.$(OBJ_SUFFIX): CXXFLAGS += -Wno-deprecated-declarations
diff -ru tamarin-central.org/build/configuration.py tamarin-central/build/configuration.py
--- tamarin-central.org/build/configuration.py	2008-04-25 11:16:16.000000000 +0900
+++ tamarin-central/build/configuration.py	2008-04-25 11:35:23.000000000 +0900
@@ -77,6 +77,8 @@
         os = 'linux'
     elif ostest.startswith('sunos'):
         os = 'sunos'
+    elif ostest.startswith('freebsd'):
+        os = 'freebsd'
     else:
         raise Exception('Unrecognized OS: ' + ostest)
 
@@ -257,6 +259,18 @@
                 'MKSTATICLIB'  : '$(AR) cr $(1)',
                 'MKPROGRAM'    : '$(CXX) -o $(1)'
                 })
+        elif self._target[0] == 'freebsd':
+            self._acvars.update({
+                'CPPFLAGS'     : os.environ.get('CPPFLAGS', ''),
+                'CXX'          : os.environ.get('CXX', 'g++'),
+                'CXXFLAGS'     : os.environ.get('CXXFLAGS', ''),
+                'DLL_CFLAGS'   : '-fPIC',
+                'LD'           : 'ar',
+                'LDFLAGS'      : '',
+                'MKSTATICLIB'  : '$(AR) cr $(1)',
+                'MKDLL'        : '$(CXX) -shared -o $(1)',
+                'MKPROGRAM'    : '$(CXX) -o $(1)'
+                })
 
     def getDebug(self):
         return self._debug
diff -ru tamarin-central.org/configure.py tamarin-central/configure.py
--- tamarin-central.org/configure.py	2008-04-25 11:16:16.000000000 +0900
+++ tamarin-central/configure.py	2008-04-25 11:45:59.000000000 +0900
@@ -162,6 +162,14 @@
     APP_CPPFLAGS += '-DAVMPLUS_CDECL '
     if config.getDebug():
         OS_LIBS.append("dl")
+elif os == "freebsd":
+    MMGC_DEFINES.update({'UNIX': None,
+                         'AVMPLUS_UNIX': None,
+                         'LINUX': None})
+    OS_LIBS.append('pthread')
+    APP_CPPFLAGS += '-DAVMPLUS_CDECL -DHAVE_PTHREAD_NP_H '
+    if config.getDebug():
+        OS_LIBS.append("dl")
 else:
     raise Exception("Unsupported OS")
 
diff -ru tamarin-central.org/manifest.mk tamarin-central/manifest.mk
--- tamarin-central.org/manifest.mk	2008-04-25 11:16:18.000000000 +0900
+++ tamarin-central/manifest.mk	2008-04-25 12:10:26.000000000 +0900
@@ -59,6 +59,9 @@
 ifeq (sunos,$(TARGET_OS))
 $(call RECURSE_DIRS,platform/unix)
 endif
+ifeq (freebsd,$(TARGET_OS))
+$(call RECURSE_DIRS,platform/unix)
+endif
 endif
 
 $(call RECURSE_DIRS,shell)