Duallicensed

Duallicensed describes software or other content that is released under two licenses at the same time, giving users the option to choose which license they will comply with. In practice, this often means a choice between an open-source license and a separate commercial or proprietary license. The dual-licensing approach is used to maximize openness and community use while creating a revenue stream from entities that need to integrate the software into proprietary products or require different support terms.

Typically, the two licenses offer the same underlying code but impose different obligations. An open-source license may require source disclosure and allow redistribution, while the commercial license might waive certain copyleft requirements, offer warranties, or provide enhanced support and indemnification. Users selecting a license must adhere to the terms of the chosen license for all redistribution, modification, and integration activities.

Dual licensing is driven by business strategy as a way to encourage broad adoption in the open-source ecosystem while selling licenses to commercial entities that want to embed the software in proprietary products or avoid copyleft obligations. It requires careful attention to license compatibility, redistribution rights, and the obligations attached to each option.

Notable examples include software projects that offer a GPL or other open-source license alongside a separate commercial license. Organizations considering dual licensing should assess their goals, the needs of potential users, and the legal implications of each license to ensure clear, compliant use.