The MIT License, the simplest license in this book, begins as follows:
Copyright (c) <year> <copyright holders>
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The <year> and <copyright holder> tags obviously refer to the date of publication of the code and the person in whom copyright is vested, which is generally going to be the creator of the code. This part of the license essentially surrenders all of the rights that the copyright holder typically receives, including, as discussed in the previous chapter, the exclusive right to commercially exploit the work and to develop derivative works from the work. In addition, the licensee may, but need not, permit its own licensees to exercise these same rights.
This grant of rights is subject to two conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. [all caps in original]
The first of these two conditions is almost universal in open source licensing and serves the straightforward and necessary purpose of alerting future users of the work of the restrictions on it. (Copyright laws used to require that copyrighted works carry an explicit notice in published forms to receive copyright protection.) The second of the two conditions provides the warranty disclaimer described in the previous chapter.