I often avoid using prewritten code from anyone besides Apple if it includes any licenses, just because I get horribly confused when I read them, no matter how simple they seem. For example, a framework I'm using has this in the header: Code: // Copyright 2010 <Framework Author> // // 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. // <Framework Name> is a Mac OS X Framework written by <Framework Author> in Objective-C 2.0 and released under the MIT Open Source License. It starts off by saying it's covered by Apache License 2.0 and then the final line says it's covered by the MIT Open Source License... which one is it? Or is it both? What must I do to comply with the licenses? I'm using this framework in an Xcode plugin which I intend to allow users to install for free, but some features of the plugin will require payment. Is that permissible under the licenses? Do I need to share some amount of my own code? Which portions, specifically, if any? Is there anything that I need to include in the plugin that's visible to the end users?