---
title: 'Maintaining Open Source Projects: Licenses'
teaser: We're pleased to announce a new chapter on Licenses in our Maintaining Open
  Source Projects book.
tags: news,open source,books
author: Tute Costa
published_on: 2015-05-01
---

We just released a new chapter of the [_Maintaining Open Source
Projects_][landing] book: "Licenses".

When we publish a new software project without any specified license, it legally
belongs to ourselves, and nobody can use or edit the project without our
explicit permission. If we want to seize the benefits of an open source
community we need to allow it to happen. The new chapter will teach you how to
do it.

There are four ways we can make a project Free Software:

1. Releasing it to the [Public Domain], without any restrictions on how it may
   be used or built upon
2. Releasing it under a "[Copyleft]" type of license, guaranteeing any
   derivative project will keep the same license. An example of a Copyleft
   license is the [General Public License (GPL)]
3. Releasing it under a "[permissive]" type of license, like the [BSD], [MIT] or
   [ISC] licenses, by which we allow anyone to use the software however they
   like, and even relicense it under different terms, provided they keep the
   copyright notice
4. [Dual-licensing] allows, for example, the use of both a Copyleft type of
   license and a proprietary one, where the software owners can sell per-copy
   exclusive licenses to organizations that want to use or redistribute the
   software under proprietary terms

Each option has its set of pros and cons, which we study in the new chapter.

[Public Domain]: https://en.wikipedia.org/wiki/Public_domain
[Copyleft]: https://en.wikipedia.org/wiki/Copyleft
[General Public License (GPL)]: https://en.wikipedia.org/wiki/GNU_General_Public_License
[permissive]: https://en.wikipedia.org/wiki/Permissive_free_software_licence
[BSD]: https://en.wikipedia.org/wiki/BSD_licenses#3-clause_license_.28.22Revised_BSD_License.22.2C_.22New_BSD_License.22.2C_or_.22Modified_BSD_License.22.29
[MIT]: https://en.wikipedia.org/wiki/MIT_License#License_terms
[ISC]: https://en.wikipedia.org/wiki/ISC_license
[Dual-licensing]: https://en.wikipedia.org/wiki/Multi-licensing

_Maintaining Open Source Projects_ is useful for you if you want to learn the
soft skills needed to grow and maintain a software project following open source
practices. It covers topics such as shaping the community, promoting your
library, keeping good communication with many different people, deciding when to
release new versions, and prioritizing all of the above.

This book is useful outside of open source too. For example, as a software
company you can embrace the practices that for years have encouraged thorough
code reviews, forthright communication, and efficient collaboration. The book is
built following the very same practices it describes, so you get access to its
GitHub repository, commits, discussions, and more.

Like our other beta books, this is a work in progress. You may find errors, but
you'll also be able to ask questions and help shape the book's development.
You'll get a $10 discount on the final price, and regular updates as we write
more chapters.

Download a [free sample][sample], and if you like it [you may buy the latest
version at a beta discount][landing]. Enjoy!

[landing]: http://maintaining-open-source.com?utm_source=giant-robots&utm_medium=blog&utm_campaign=new-chapter
[sample]: http://thoughtbot.com/maintaining-open-source-projects-sample.pdf