--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Declares base types allowed on the platform.
+module platform
+
+import end
+
+# Root of everything.
+class Object
+ # Used for comparisons.
+ type OTHER: nullable Object
+
+ # Is `other` equqls to `self`?
+ fun ==(other: OTHER): Bool is intern
+
+ # Is `other` different from `self`?
+ fun !=(other: OTHER): Bool do return not self == other
+end
+
+# Some services about Integers.
+class Int
+ fun -: Int is intern
+ fun +(i: Int): Int is intern
+ fun -(i: Int): Int is intern
+ fun *(i: Int): Int is intern
+ fun /(i: Int): Int is intern
+ fun >(i: Int): Bool is intern
+ fun to_f: Float is intern
+end
+
+# Some services about Floats.
+class Float
+ fun +(f: Float): Float is intern
+ fun -(f: Float): Float is intern
+ fun *(f: Float): Float is intern
+ fun /(f: Float): Float is intern
+ fun >(f: Float): Bool is intern
+end
+
+# Booleans, `true` or `false`.
+class Bool end
+
+# Strings (there is no chars...).
+class String end
+
+# List of things.
+class List[E] end