Open-Source License
A copyright license that grants users the right to access, modify, and redistribute the source code of software, subject to specified obligations. Divided between permissive licenses (MIT, Apache, BSD) imposing minimal conditions, and copyleft licenses (GPL, AGPL, LGPL) requiring derivative works to be released under the same license.
An open-source license is a copyright license that grants users the right to access, modify, and redistribute the source code of software, subject to specified conditions. Open-source licenses fall into two principal categories: permissive licenses (MIT, Apache 2.0, BSD), which impose minimal obligations on downstream users; and copyleft licenses (GPL, AGPL, LGPL), which require derivative works to be released under the same license. The choice between categories has substantial commercial consequences.
Permissive licenses
MIT, Apache 2.0, and BSD licenses permit virtually any use, modification, or redistribution, with only modest attribution and notice obligations. The Apache 2.0 license adds an explicit patent grant from contributors and a patent-retaliation clause. Permissive licenses do not require derivative works to be open-sourced. Most modern enterprise software stacks combine code under permissive licenses with proprietary code without infecting the proprietary portion.
Copyleft licenses
The GNU General Public License (GPL) requires that any derivative work distributed to third parties be made available under the same GPL terms, including the requirement to provide source code. This is the "copyleft" obligation. The Lesser GPL (LGPL) softens this for libraries linked to proprietary code. The Affero GPL (AGPL) extends the obligation to network use, running AGPL software on a server accessed by users over a network triggers the source-code obligation, even without distribution.
License compatibility and stacking
Combining code under different open-source licenses is permissible only when the licenses are compatible. GPL is incompatible with most non-GPL licenses for purposes of linking GPL code into a larger work. Apache 2.0 and GPL v2 are incompatible; Apache 2.0 and GPL v3 are compatible (in one direction). Compatibility analysis is fact-specific and should be done before any code is incorporated into a commercial product.
Commercial risk in copyleft
The principal commercial risk is unintended copyleft contamination of proprietary code. Static linking to GPL libraries, incorporating GPL code into a proprietary application, or using AGPL code in a SaaS deployment can trigger source-code disclosure obligations covering the entire combined work. Texas software companies acquiring code from contractors or in M&A should perform license audits as part of due diligence.
Open-source license obligations have become a standard M&A diligence item, buyers run automated license-scanning tools across the target's codebase. Texas businesses building software products should maintain a software bill of materials (SBOM) tracking every open-source dependency and its license. The cost of a license-compliance program is small compared to the cost of GPL contamination discovered during a sale process.