diff --git a/SCons/Config/gnu b/SCons/Config/gnu
index 6bb5d813..2da0c7f8 100644
--- a/SCons/Config/gnu
+++ b/SCons/Config/gnu
@@ -255,6 +255,13 @@ if conf.CheckBigEndian():
 	test_env.Append(CPPDEFINES = ['__BIG_ENDIAN__'])
 conf.Finish()
 
+if makensis_env['PLATFORM'] == 'hpux':
+	makensis_env.Append(CPPDEFINES = ['__ALLOW_UNALIGNED_DATA_ACCESS__'])
+	makensis_conf = makensis_env.Configure()
+	makensis_conf.CheckLib("unalign")
+	makensis_conf.CheckLib("hppa")
+	makensis_conf.Finish()
+
 ### return
 
 Return('stub_env makensis_env plugin_env util_env cp_util_env test_env')
diff --git a/SCons/Config/hpc++ b/SCons/Config/hpc++
new file mode 100644
index 00000000..3c0ebd1d
--- /dev/null
+++ b/SCons/Config/hpc++
@@ -0,0 +1,113 @@
+print "Using hpc++ tools configuration"
+
+Import('defenv')
+
+### flags
+
+defenv['ENTRY_FLAG'] = lambda x: ''
+defenv['MAP_FLAG'] = ''
+defenv['EXCEPTION_FLAG'] = ''
+defenv['NODEFLIBS_FLAG'] = ''
+defenv['C_FLAG'] = ''
+defenv['CPP_FLAG'] = ''
+defenv['CPP_REQUIRES_STDLIB'] = 0
+defenv['SUBSYS_CON'] = ''
+defenv['MSVCRT_FLAG'] = ''
+
+### stub environment
+
+stub_env = defenv.Clone()
+
+### makensis environment
+
+makensis_env = defenv.Clone()
+
+### use "$CXX -Ae" as the "$CC" compiler to build makensis
+
+makensis_env['CC'] = makensis_env['CXX']
+makensis_env.Append(CFLAGS = '-Ae')
+
+### required to build makensis
+
+makensis_env.Append(LINKFLAGS = '+DD32')
+makensis_env.Append(LINKFLAGS = '-mt')
+
+makensis_env.Append(CCFLAGS = '+DD32')
+makensis_env.Append(CCFLAGS = '-mt')
+
+### debug for makensis
+
+if makensis_env['DEBUG']:
+	makensis_env.Append(CCFLAGS = '-g')
+	makensis_env.Append(LINKFLAGS = '-g')
+
+### strip for makensis
+
+if not makensis_env['DEBUG'] and makensis_env['STRIP']:
+	makensis_env.Append(LINKFLAGS = '-s')
+
+#
+# aCC defines _BIG_ENDIAN, but we use __BIG_ENDIAN__ so check and define as
+# needed (is there any HPUX that is NOT big endian?).
+#
+
+def check_big_endian(ctx):
+	ctx.Message('Checking for if this is a big endian host... ')
+	test = """
+		#define LITTLE_ENDIAN 0
+		#define BIG_ENDIAN 1
+		#define UNKNOWN 2
+		int main()
+		{
+			union {
+				short s;
+				char c[sizeof(short)];
+			} u;
+			u.s = 0x0102;
+			if (sizeof(short) == 2) {
+				if (u.c[0] == 1 && u.c[1] == 2)
+					return (BIG_ENDIAN);
+				else if (u.c[0] == 2 && u.c[1] == 1)
+					return (LITTLE_ENDIAN);
+				else
+					return(UNKNOWN);
+			} else {
+				return (sizeof(short));
+			}
+		}
+	"""
+	result = not ctx.TryRun(test, '.c')[0]
+	ctx.Result(result)
+	return result
+
+makensis_conf = makensis_env.Configure(custom_tests = { 'CheckBigEndian' : check_big_endian })
+
+if makensis_conf.CheckBigEndian():
+	makensis_env.Append(CPPDEFINES = ['__BIG_ENDIAN__'])
+
+if makensis_env['PLATFORM'] == 'hpux':
+	makensis_env.Append(CPPDEFINES = ['__ALLOW_UNALIGNED_DATA_ACCESS__'])
+	makensis_conf.CheckLib("unalign")
+	makensis_conf.CheckLib("hppa")
+
+makensis_conf.Finish()
+
+### plugin environment
+
+plugin_env = defenv.Clone(no_import_lib = 1)
+
+### util environment
+
+util_env = defenv.Clone()
+
+### cross-platform util environment
+
+cp_util_env = util_env.Clone()
+
+### test environment
+
+test_env = defenv.Clone()
+
+# return
+
+Return('stub_env makensis_env plugin_env util_env cp_util_env test_env')
diff --git a/SConstruct b/SConstruct
index 75ee0620..bc488f28 100644
--- a/SConstruct
+++ b/SConstruct
@@ -57,11 +57,17 @@ doc = [
 #######  Build Environment                                         ###
 ######################################################################
 
+path = ARGUMENTS.get('PATH', '')
 toolset = ARGUMENTS.get('TOOLSET', '')
 
-if toolset:
-	defenv = Environment(TOOLS = toolset.split(',') + ['zip'])
+if toolset and path:
+	defenv = Environment(ENV = {'PATH' : path}, TOOLS = toolset.split(',') + ['zip'])
 else:
+	if path:
+		defenv = Environment(ENV = {'PATH' : path})
+	if toolset:
+		defenv = Environment(TOOLS = toolset.split(',') + ['zip'])
+if not toolset and not path:
 	defenv = Environment()
 
 Export('defenv')
@@ -136,6 +142,7 @@ opts.Add(ListOption('SKIPDOC', 'A list of doc files that will not be built/insta
 opts.Add(('SKIPTESTS', 'A comma-separated list of test files that will not be ran', 'none'))
 opts.Add(('IGNORETESTS', 'A comma-separated list of test files that will be ran but ignored', 'none'))
 # build tools
+opts.Add(('PATH', 'A colon-separated list of system paths instead of the default - TEMPORARY AND MAY DEPRECATE', None))
 opts.Add(('TOOLSET', 'A comma-separated list of specific tools used for building instead of the default', None))
 opts.Add(BoolOption('MSTOOLKIT', 'Use Microsoft Visual C++ Toolkit', 'no'))
 opts.Add(BoolOption('CHMDOCS', 'Build CHM documentation, requires hhc.exe', hhc))
@@ -339,6 +346,8 @@ if 'msvc' in tools or 'mstoolkit' in tools:
 	envs = SConscript('SCons/Config/ms')
 elif 'gcc' in tools:
 	envs = SConscript('SCons/Config/gnu')
+elif 'hpc++' in tools:
+	envs = SConscript('SCons/Config/hpc++')
 else:
 	envs = SConscript('SCons/Config/default')
 
diff --git a/Source/Plugins.cpp b/Source/Plugins.cpp
index 2ea9f5ea..9c2999e5 100644
--- a/Source/Plugins.cpp
+++ b/Source/Plugins.cpp
@@ -69,7 +69,7 @@ size_t file_size(ifstream& file) {
   file.seekg(0, ios::end);
 
   ifstream::pos_type result = file.tellg();
-  assert(result >= 0);
+  assert(result >= (ifstream::pos_type)0);
 
   file.seekg(pos);
 
diff --git a/Source/ResourceEditor.cpp b/Source/ResourceEditor.cpp
index da100940..78d5d7f8 100644
--- a/Source/ResourceEditor.cpp
+++ b/Source/ResourceEditor.cpp
@@ -27,6 +27,12 @@ using namespace std;
 #define ALIGN(dwToAlign, dwAlignOn) dwToAlign = (dwToAlign%dwAlignOn == 0) ? dwToAlign : dwToAlign - (dwToAlign%dwAlignOn) + dwAlignOn
 #define RALIGN(dwToAlign, dwAlignOn) ((dwToAlign%dwAlignOn == 0) ? dwToAlign : dwToAlign - (dwToAlign%dwAlignOn) + dwAlignOn)
 
+#ifndef _WIN32
+static inline ULONG ConvertEndianness(ULONG u) {
+  return FIX_ENDIAN_INT32(u);
+}
+#endif
+
 static inline DWORD ConvertEndianness(DWORD d) {
   return FIX_ENDIAN_INT32(d);
 }
diff --git a/Source/makenssi.cpp b/Source/makenssi.cpp
index 7feaacb7..9e791905 100644
--- a/Source/makenssi.cpp
+++ b/Source/makenssi.cpp
@@ -245,6 +245,12 @@ static int change_to_script_dir(CEXEBuild& build, string& script)
 
 int main(int argc, char **argv)
 {
+
+#ifdef __ALLOW_UNALIGNED_DATA_ACCESS__
+  extern "C" void allow_unaligned_data_access();
+  allow_unaligned_data_access();
+#endif
+
   CEXEBuild build;
   int do_cd=1;
   int outputtried=0;