Software License Types: A Complete Guide for Businesses

Software license types define the legal terms under which software can be used, modified, and distributed. Whether you are choosing a license for your own application or evaluating third-party software for your business, understanding the different types of software license agreement is essential for protecting your rights and avoiding legal exposure.

This article covers the major software licence types and their practical implications. It is educational content, not legal advice. Consult an attorney for licensing questions specific to your situation.

What Is a Software License?

A software license is a legal agreement between the software creator (licensor) and the user (licensee) that defines the terms under which the software may be used. Without a license, the software is protected by copyright law, and users have no legal permission to use, copy, or modify it.

Software licenses serve several critical functions:

• Define usage rights. Specify how many users, devices, or installations are permitted.
• Set modification rules. State whether users can alter the source code and under what conditions.
• Control distribution. Determine whether users can share, resell, or sublicense the software.
• Limit liability. Protect the developer from legal claims arising from software use.
• Establish warranties. Clarify what the developer guarantees (or disclaims) about software performance.

Every piece of software distributed to users should include a license. If you are building a software product, you can use an EULA generator to create a license agreement tailored to your distribution model.

Proprietary Software Licenses

Proprietary licenses are the most restrictive software license types. The software creator retains full ownership, and users receive only a limited right to use the software under specific conditions.

Key characteristics

• Source code is not provided to users
• Users cannot modify, reverse-engineer, or redistribute the software
• Usage is typically limited to a specific number of users, devices, or locations
• The license can be revoked if terms are violated

Common proprietary licensing models

Proprietary licenses come in several commercial structures:

1. Per-user license. Each individual user requires a separate license. Common in desktop software and professional tools.
2. Per-device license. The license is tied to a specific machine or hardware identifier. Used frequently in embedded systems and industrial software.
3. Site license. Grants usage rights to all users within a specific physical location or organization. Simplifies administration for large deployments.
4. Concurrent use license. Limits the number of simultaneous users rather than total users. A 50-seat concurrent license allows any number of registered users, but only 50 can be active at once.
5. Subscription license. Access is granted for a recurring fee, typically monthly or annually. If the subscription lapses, access ends. This model has become the dominant approach for SaaS products and modern desktop applications.
6. Perpetual license. A one-time purchase granting indefinite usage rights, sometimes with an optional annual maintenance fee for updates and support.

Enterprise license agreements

Large organizations often negotiate enterprise license agreements (ELAs) that bundle multiple products, include volume discounts, and define custom terms. ELAs typically cover:

• Minimum purchase commitments
• True-up provisions for additional usage
• Support and maintenance terms
• Audit rights allowing the vendor to verify compliance

Open Source Software License Types

Open source licenses grant users the freedom to use, study, modify, and distribute software. However, not all open source licenses work the same way. The two major categories are permissive licenses and copyleft licenses.

Permissive licenses

Permissive licenses impose minimal restrictions on how you can use the software. They allow you to incorporate open source code into proprietary products without requiring you to release your own source code.

The most widely used permissive licenses include:

• MIT License. One of the simplest and most popular. Permits commercial use, modification, and distribution. Requires only that the original copyright notice and license text be included in copies. No warranty is provided.
• Apache License 2.0. Similar to MIT but includes an explicit patent grant, protecting users from patent claims by contributors. Also requires preservation of copyright notices and a NOTICE file if one exists.
• BSD Licenses (2-Clause and 3-Clause). The 2-Clause BSD License is nearly identical to MIT. The 3-Clause version adds a restriction preventing the use of contributor names for endorsement without permission.
• ISC License. Functionally equivalent to MIT and 2-Clause BSD but uses simpler language. Popular in the Node.js ecosystem.

Permissive licenses are the safest choice for businesses incorporating open source components into commercial products. They allow maximum flexibility with minimal legal risk.

Copyleft licenses

Copyleft licenses require that derivative works be distributed under the same license terms. This ensures the software and its modifications remain open source.

The major copyleft licenses include:

• GNU General Public License (GPL) v2 and v3. The most widely known copyleft license. Any software that includes GPL-licensed code must also be released under the GPL if distributed. GPLv3 adds protections against patent claims and anti-circumvention laws.
• GNU Lesser General Public License (LGPL). A weaker copyleft that allows proprietary software to link against LGPL libraries without triggering the copyleft requirement. The LGPL code itself must remain open source, but your proprietary code that merely uses the library does not.
• GNU Affero General Public License (AGPL). Extends GPL to cover software accessed over a network. If you modify AGPL software and make it available as a web service, you must release your modifications. This closes the "SaaS loophole" in standard GPL.
• Mozilla Public License (MPL) 2.0. A file-level copyleft. Modifications to MPL-licensed files must remain under MPL, but you can combine them with proprietary files in the same project without affecting your proprietary code's licensing.

Choosing between permissive and copyleft

The right choice depends on your goals:

• If you want maximum adoption and allow commercial use, choose a permissive license (MIT, Apache 2.0).
• If you want to ensure all modifications remain open source, choose a copyleft license (GPL, AGPL).
• If you want a middle ground that protects your code while allowing integration with proprietary software, consider LGPL or MPL.

Software License Types for SaaS and Cloud Products

Traditional software licensing was designed for software distributed as copies. SaaS and cloud products require different approaches because users access the software over the internet rather than installing it locally.

Subscription agreements

Most SaaS products use subscription-based terms of service rather than traditional software licenses. These agreements typically cover:

• Service availability and uptime commitments
• Data ownership, processing, and portability
• Usage limits (users, API calls, storage, bandwidth)
• Acceptable use policies
• Termination and data export rights

If you operate a SaaS product, your terms of service should clearly define these elements. Your privacy policy must also explain how you handle user data, which is a legal requirement under regulations like the GDPR and CCPA.

API licenses

When your software exposes APIs for third-party integration, you need a separate API license or developer agreement that addresses:

• Rate limits and usage quotas
• Permitted use cases (and prohibited ones)
• Attribution requirements
• Data handling obligations for API consumers
• Revocation conditions

Open core model

Some companies release a core product under an open source license while offering proprietary extensions, plugins, or enterprise features under a commercial license. This hybrid approach lets the open source community contribute to the core while generating revenue from premium features.

Creative Commons and Other Non-Software Licenses

While this guide focuses on software licence types, it is worth understanding licenses that apply to non-code assets often bundled with software.

• Creative Commons (CC) licenses. Designed for creative works like documentation, images, and educational content. The CC suite includes options for allowing or restricting commercial use, modifications, and share-alike requirements. CC licenses are not recommended for software.
• Public domain dedications (CC0, Unlicense). The creator waives all rights, placing the work in the public domain. Anyone can use the work for any purpose without restriction or attribution.
• Dual licensing. Some projects offer their software under two licenses simultaneously, typically an open source license for community use and a commercial license for businesses that want to avoid copyleft obligations. MySQL and Qt have historically used this model.

Software License Compliance: What Businesses Must Know

Using software without complying with its license terms exposes your business to legal and financial risk. License violations can result in lawsuits, injunctions, and significant damages.

Compliance obligations

Every type of software license agreement imposes specific obligations:

• Attribution. Most open source licenses require you to include the original copyright notice and license text in your product. Failing to do so is a license violation even if unintentional.
• Source code disclosure. Copyleft licenses require you to provide source code to recipients of your software. For GPL software, you must offer the complete corresponding source code.
• Patent grants. Licenses like Apache 2.0 include patent grants from contributors. Using the software means you benefit from those grants, but contributing to the project may create reciprocal obligations.
• License compatibility. Not all open source licenses are compatible with each other. Combining MIT-licensed code with GPL-licensed code is allowed (the result is GPL), but combining Apache 2.0 with GPLv2 can create conflicts.

Software composition analysis

Modern applications typically include dozens or hundreds of open source dependencies. Software composition analysis (SCA) tools scan your codebase to:

1. Identify all open source components and their licenses
2. Flag license conflicts between dependencies
3. Detect known security vulnerabilities in dependencies
4. Generate license compliance reports and notices
5. Alert you when dependency licenses change between versions

Running SCA as part of your build pipeline catches compliance issues before they reach production.

Audit preparedness

Software vendors, particularly enterprise vendors, often include audit rights in their license agreements. Being prepared for a license audit means:

• Maintaining accurate records of all software purchases and license keys
• Tracking actual usage against licensed quantities
• Documenting open source components and their licenses (a software bill of materials)
• Keeping proof of compliance for copyleft obligations (source code availability)

How Software License Types Affect Your Legal Documents

Your choice of software license has direct implications for the legal documents on your website and product.

End-user license agreements

If you distribute proprietary software, you need an EULA that covers installation, usage restrictions, intellectual property ownership, warranty disclaimers, and limitation of liability. An EULA generator can help you create a comprehensive agreement tailored to your software distribution model.

Privacy policies and data collection

Regardless of license type, if your software collects personal data, you are legally required to maintain a privacy policy. Article 13 of the GDPR requires you to inform users about data collection at the point of collection. CCPA Section 1798.100 requires businesses to disclose the categories of personal information collected. Tools like TermsBox can help you generate and maintain a privacy policy that stays current with your data practices.

Terms of service

SaaS and web-based software require terms of service that define the relationship between you and your users. These terms should address subscription billing, acceptable use, service level commitments, data handling, and dispute resolution.

Disclaimer notices

Software provided "as is" should include appropriate disclaimers limiting liability. This applies to both proprietary and open source software. Nearly all open source licenses include warranty disclaimers, and your commercial license should do the same. A disclaimer generator can help create appropriate notices for your specific situation.

Software License Types: Comparison Table

Here is a summary of the most common software license types and their key attributes:

Proprietary licenses

• Usage rights: Limited to license terms
• Source code access: Not provided
• Modification allowed: No
• Redistribution allowed: No
• Commercial use: As defined in license
• Best for: Commercial software products, enterprise tools

Permissive open source (MIT, Apache, BSD)

• Usage rights: Broad
• Source code access: Provided
• Modification allowed: Yes
• Redistribution allowed: Yes (with attribution)
• Commercial use: Yes
• Best for: Libraries, frameworks, developer tools seeking maximum adoption

Copyleft open source (GPL, AGPL)

• Usage rights: Broad with conditions
• Source code access: Provided
• Modification allowed: Yes (must share modifications)
• Redistribution allowed: Yes (under same license)
• Commercial use: Yes (but derivatives must be open source)
• Best for: Projects that want to ensure all versions remain open source

Weak copyleft (LGPL, MPL)

• Usage rights: Broad with limited conditions
• Source code access: Provided
• Modification allowed: Yes (modifications to licensed files must be shared)
• Redistribution allowed: Yes
• Commercial use: Yes (proprietary code can link to licensed libraries)
• Best for: Libraries that want broad adoption while keeping modifications open

Frequently Asked Questions

What are the main types of software licenses?

The main software license types are proprietary licenses, open source licenses (permissive and copyleft), freemium licenses, and public domain dedications. Proprietary licenses restrict use and distribution, while open source licenses grant users freedom to use, modify, and share the software under specified conditions.

What is the difference between permissive and copyleft licenses?

Permissive licenses like MIT and Apache 2.0 allow you to use, modify, and redistribute software with minimal restrictions, including in proprietary products. Copyleft licenses like GPL require that derivative works also be released under the same license terms, which means your modifications must remain open source.

Do I need a software license for my application?

Yes. If you distribute software to users, whether as a download, SaaS product, or mobile app, you need a license agreement that defines usage rights, limitations, and liability protections. Without a license, users have no clear legal right to use your software, and you have no legal protection against misuse.

Can I use open source software in a commercial product?

Yes, but the license terms determine how. Permissive licenses like MIT and BSD allow commercial use with minimal obligations. Copyleft licenses like GPL require you to release your source code under the same license if you distribute the combined work. Always review the specific license terms before incorporating open source components.