LicenseExpressionFAQ

Why was the License Terms Expression Language introduced in the SPDX 2.0 Specification

The SPDX 1.x Specification and earlier versions of the License List had a limited ability to represent more complex license situations typically found in practice. Examples of such complexity can be found at: http://wiki.spdx.org/view/FileNoticeExamples . Additionally, earlier versions of the SPDX License List required the addition of multiple yet similar license identifiers in order to capture combinations of versions, the “or later” license genre (i.e. GPL-2.0 and GPL-2.0+) and the most common exceptions (e.g., GPL-2.0+-with-autoconf-exception or GPL-3.0-with-autoconf-exception). The SPDX Legal working group identified more than 30 additional distinct exceptions. If one tried to accommodate the many different permutations of the different exceptions with the “or later” cases, the license list would become bloated and unwieldy. For additional historical background information you can reference: http://wiki.spdx.org/view/Legal_Team/License_Expression_Review_1. All in all, the introduction of the WITH and ‘+” operators, and the additional of the new license list exceptions section, we are able to represent more sets of license terms found in practice while simultaneously streamlining the SPDX License List.