Common Open Source Licenses: BSD, Apache, GPL, LGPL, MIT, MPL, and EPL Overview

There are hundreds of open source licenses; this article introduces several common ones: BSD, Apache License 2.0, GPL, LGPL, MIT, MPL, and EPL.

BSD

BSD (Berkeley Software Distribution) is a permissive license that allows free use, modification, and redistribution of source or binary forms, provided three conditions are met:

If the distributed product contains source code, the original BSD license must be included in the source.

If only binary libraries/software are distributed, the original BSD license must be included in the documentation and copyright notice.

The original author’s or organization’s name and the original product name cannot be used for marketing.

BSD encourages code sharing and permits commercial use, making it popular for companies that want full control over third‑party code.

Apache License

The Apache License, created by the Apache Software Foundation, is a permissive license similar to BSD. It encourages code sharing, requires preservation of copyright notices, and is friendly to commercial applications.

Key obligations include:

Providing a copy of the Apache License to users.

Indicating any modifications made to the code.

Including original license, trademark, patent, and other required notices in derivative works.

If a NOTICE file is distributed, it must contain the Apache License and may include additional notices, but must not appear to modify the Apache License.

Example of an Apache License 2.0 header:

Copyright [yyyy] [name of copyright owner]

Licensed under the Apache License, Version 2.0 ("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.

GPL

GPL (GNU General Public License) requires that any software that incorporates GPL‑licensed code must also be released under GPL, prohibiting the creation of closed‑source commercial products from such code.

LGPL

LGPL (Lesser GPL) is a variant of GPL designed for libraries. It allows commercial software to link to LGPL‑licensed libraries without having to open‑source the entire application, provided modifications to the LGPL library itself are released under LGPL.

MIT

MIT is a highly permissive license originating from the Massachusetts Institute of Technology. It requires only that the original copyright notice and permission notice be included in source or binary distributions, allowing unrestricted commercial use.

MPL (Mozilla Public License 1.1)

MPL permits free redistribution and modification but requires that modifications be contributed back to the original project, while not imposing linking requirements on combined works.

EPL (Eclipse Public License 1.0)

EPL allows unrestricted use, copying, distribution, and modification, including closed‑source commercial redistribution, provided that the source code remains available under EPL when required and that EPL‑covered components are clearly identified.

Conclusion

Using GPL‑licensed software “infects” your product with the GPL, which is often unsuitable for commercial developers in China. In contrast, LGPL, Apache, and BSD licenses impose only attribution requirements, making them more appropriate for commercial applications.

When selecting open‑source software, understand your intended use and choose a license that aligns with your commercial needs.