diff --git a/base/poco/Foundation/include/Poco/Platform.h b/base/poco/Foundation/include/Poco/Platform.h
index 6623b25781e..87fa440fa5f 100644
--- a/base/poco/Foundation/include/Poco/Platform.h
+++ b/base/poco/Foundation/include/Poco/Platform.h
@@ -238,24 +238,14 @@
 #    define POCO_COMPILER_MINGW
 #elif defined(__INTEL_COMPILER) || defined(__ICC) || defined(__ECC) || defined(__ICL)
 #    define POCO_COMPILER_INTEL
-#elif defined(__SUNPRO_CC)
-#    define POCO_COMPILER_SUN
 #elif defined(__MWERKS__) || defined(__CWCC__)
 #    define POCO_COMPILER_CODEWARRIOR
 #elif defined(__sgi) || defined(sgi)
 #    define POCO_COMPILER_SGI
-#elif defined(__HP_aCC)
-#    define POCO_COMPILER_HP_ACC
 #elif defined(__BORLANDC__) || defined(__CODEGEARC__)
 #    define POCO_COMPILER_CBUILDER
 #elif defined(__DMC__)
 #    define POCO_COMPILER_DMARS
-#elif defined(__DECCXX)
-#    define POCO_COMPILER_COMPAC
-#elif (defined(__xlc__) || defined(__xlC__)) && defined(__IBMCPP__)
-#    define POCO_COMPILER_IBM_XLC // IBM XL C++
-#elif defined(__IBMCPP__) && defined(__COMPILER_VER__)
-#    define POCO_COMPILER_IBM_XLC_ZOS // IBM z/OS C++
 #endif
 
 
diff --git a/base/poco/Foundation/include/Poco/Platform_POSIX.h b/base/poco/Foundation/include/Poco/Platform_POSIX.h
index cc2667bdac8..96f0c32cb9e 100644
--- a/base/poco/Foundation/include/Poco/Platform_POSIX.h
+++ b/base/poco/Foundation/include/Poco/Platform_POSIX.h
@@ -25,9 +25,6 @@
 #if defined(hpux) || defined(_hpux)
 #    if defined(__hppa) || defined(__hppa__)
 #        define POCO_NO_SYS_SELECT_H 1
-#        if defined(__HP_aCC)
-#            define POCO_NO_TEMPLATE_ICOMPARE 1
-#        endif
 #    endif
 #endif
 
diff --git a/base/poco/Foundation/include/Poco/String.h b/base/poco/Foundation/include/Poco/String.h
index 90168ede895..2ac03d38aed 100644
--- a/base/poco/Foundation/include/Poco/String.h
+++ b/base/poco/Foundation/include/Poco/String.h
@@ -429,13 +429,7 @@ S translateInPlace(S & str, const typename S::value_type * from, const typename
     poco_check_ptr(from);
     poco_check_ptr(to);
     str = translate(str, S(from), S(to));
-#if defined(__SUNPRO_CC)
-    // Fix around the RVO bug in SunStudio 12.4
-    S ret(str);
-    return ret;
-#else
     return str;
-#endif
 }
 
 
diff --git a/base/poco/Foundation/include/Poco/Types.h b/base/poco/Foundation/include/Poco/Types.h
index 85256e8dcea..327aea02286 100644
--- a/base/poco/Foundation/include/Poco/Types.h
+++ b/base/poco/Foundation/include/Poco/Types.h
@@ -55,123 +55,6 @@ typedef unsigned long long UInt64;
 #        endif
 #    endif
 #    define POCO_HAVE_INT64 1
-#elif defined(__DECCXX)
-//
-// Compaq C++
-//
-typedef signed char Int8;
-typedef unsigned char UInt8;
-typedef signed short Int16;
-typedef unsigned short UInt16;
-typedef signed int Int32;
-typedef unsigned int UInt32;
-typedef signed __int64 Int64;
-typedef unsigned __int64 UInt64;
-typedef signed long IntPtr;
-typedef unsigned long UIntPtr;
-#    define POCO_PTR_IS_64_BIT 1
-#    define POCO_LONG_IS_64_BIT 1
-#    define POCO_HAVE_INT64 1
-#elif defined(__HP_aCC)
-//
-// HP Ansi C++
-//
-typedef signed char Int8;
-typedef unsigned char UInt8;
-typedef signed short Int16;
-typedef unsigned short UInt16;
-typedef signed int Int32;
-typedef unsigned int UInt32;
-typedef signed long IntPtr;
-typedef unsigned long UIntPtr;
-#    if defined(__LP64__)
-#        define POCO_PTR_IS_64_BIT 1
-#        define POCO_LONG_IS_64_BIT 1
-typedef signed long Int64;
-typedef unsigned long UInt64;
-#    else
-typedef signed long long Int64;
-typedef unsigned long long UInt64;
-#    endif
-#    define POCO_HAVE_INT64 1
-#elif defined(__SUNPRO_CC)
-//
-// SUN Forte C++
-//
-typedef signed char Int8;
-typedef unsigned char UInt8;
-typedef signed short Int16;
-typedef unsigned short UInt16;
-typedef signed int Int32;
-typedef unsigned int UInt32;
-typedef signed long IntPtr;
-typedef unsigned long UIntPtr;
-#    if defined(__sparcv9)
-#        define POCO_PTR_IS_64_BIT 1
-#        define POCO_LONG_IS_64_BIT 1
-typedef signed long Int64;
-typedef unsigned long UInt64;
-#    else
-typedef signed long long Int64;
-typedef unsigned long long UInt64;
-#    endif
-#    define POCO_HAVE_INT64 1
-#elif defined(__IBMCPP__)
-//
-// IBM XL C++
-//
-typedef signed char Int8;
-typedef unsigned char UInt8;
-typedef signed short Int16;
-typedef unsigned short UInt16;
-typedef signed int Int32;
-typedef unsigned int UInt32;
-typedef signed long IntPtr;
-typedef unsigned long UIntPtr;
-#    if defined(__64BIT__)
-#        define POCO_PTR_IS_64_BIT 1
-#        define POCO_LONG_IS_64_BIT 1
-typedef signed long Int64;
-typedef unsigned long UInt64;
-#    else
-typedef signed long long Int64;
-typedef unsigned long long UInt64;
-#    endif
-#    define POCO_HAVE_INT64 1
-#elif defined(__sgi)
-//
-// MIPSpro C++
-//
-typedef signed char Int8;
-typedef unsigned char UInt8;
-typedef signed short Int16;
-typedef unsigned short UInt16;
-typedef signed int Int32;
-typedef unsigned int UInt32;
-typedef signed long IntPtr;
-typedef unsigned long UIntPtr;
-#    if _MIPS_SZLONG == 64
-#        define POCO_PTR_IS_64_BIT 1
-#        define POCO_LONG_IS_64_BIT 1
-typedef signed long Int64;
-typedef unsigned long UInt64;
-#    else
-typedef signed long long Int64;
-typedef unsigned long long UInt64;
-#    endif
-#    define POCO_HAVE_INT64 1
-#elif defined(_DIAB_TOOL)
-typedef signed char Int8;
-typedef unsigned char UInt8;
-typedef signed short Int16;
-typedef unsigned short UInt16;
-typedef signed int Int32;
-typedef unsigned int UInt32;
-typedef signed long IntPtr;
-typedef unsigned long UIntPtr;
-typedef signed long long Int64;
-typedef unsigned long long UInt64;
-#    define POCO_HAVE_INT64 1
 #endif