VBMAN License Usage Guide
This document helps you quickly understand the licensing requirements of the VBMAN project and when you need to pay for a commercial license.
Core Points of the Existing License
Base License: GPL-3.0
VBMAN is licensed under the GNU General Public License v3.0 (GPL-3.0) open source license.
One-Sentence Summary
Using compiled DLL → Completely Free
Modifying source code and open-sourcing → Completely Free
Using DLL is free; modifying source code and using it closed-source requires payment.
Detailed Explanation
1. Binary Files (Permanently Free)
VBMAN compiled binary files (.dll, .exe, etc.) are permanently free with no usage restrictions:
- ✅ Personal projects — Free
- ✅ Commercial software directly referencing VBMAN DLL — Free
- ✅ Internal company tool development — Free
- ✅ Open source projects — Free
2. Source Code Usage
Case 1: Free Usage (Complying with GPL)
If you meet any of the following conditions, you can use the source code for free:
- Personal learning/research — Modifying for your own use, not distributed externally
- Modified and open-sourced — If you modify VBMAN and distribute it (including selling), you must open-source the entire project under a GPL-compatible license
Core GPL Requirements:
- Must include LICENSE file when distributing
- Modified works must also be open-sourced under GPL
- Retain copyright notices and disclaimers
Case 2: Requires Commercial License
Only one situation requires payment:
You want to use VBMAN source code in a closed-source commercial project and do not want to open-source your own code.
Common scenarios:
| Scenario | Description |
|---|---|
| Modified VBMAN source code but don't want to open-source modifications | Requires commercial license |
| Integrated VBMAN source code into closed-source product for sale | Requires commercial license |
| SaaS service using modified VBMAN source code but closed-source deployment | Requires commercial license |
Decision Flowchart
┌─────────────────────────────────────┐
│ Do you want to use VBMAN for │
│ commercial purposes? │
└──────────────────┬──────────────────┘
│
┌─────────┴─────────┐
▼ ▼
┌──────────┐ ┌──────────┐
│ Use DLL │ │ Use Source │
│ Only │ │ Code │
└────┬─────┘ └────┬─────┘
│ │
▼ ▼
┌──────────┐ ┌──────────────┐
│ Free │ │ Distribute? │
│ No │ └──────┬───────┘
│ License │ │
│ Required │ ┌──────┴──────┐
└──────────┘ ▼ ▼
┌──────────┐ ┌──────────┐
│Closed │ │ Open │
│Source │ │ Source │
└────┬─────┘ └────┬─────┘
│ │
▼ ▼
┌──────────┐ ┌──────────┐
│Purchase │ │Completely│
│Commercial│ │ Free │
│License │ │ GPL │
└──────────┘ └──────────┘Summary
Definition of Payment Situations
1. Binary Files (DLL, EXE, etc.)
- Permanently free
- No usage restrictions
- Whether for personal or commercial use
2. Source Code Usage - Individual Users
- Free to use
- But must comply with GPL license requirements:
- Must include LICENSE file when distributing
- Modified works must also be open-sourced under GPL-compatible license
3. Source Code Usage - Commercial Scenarios
There are two situations here:
Scenario A: Open Source Commercial Use (Free)
- If your commercial project is based on modifications or secondary development of this project
- And when distributing/selling, you open-source the entire project's source code under a GPL-compatible license
- In this case, no payment is required
Scenario B: Closed Source Commercial Use (Requires Payment)
- If you want to use this project's source code in a closed-source commercial project
- That is, you don't want to open-source your own code
- You must contact the author to purchase a commercial license
Specific Scenarios Requiring Payment
- Commercial software company developing closed-source products using VBMAN source code
- Internal closed-source enterprise systems using VBMAN source code and not wanting to follow GPL open-source requirements
- SaaS service providers building services on closed-source code
Scenarios Not Requiring Payment
- Directly using compiled DLL/EXE files, whether for personal or commercial use
- Personal learning and research using source code
- Projects based on source code development that are willing to open-source modified code
- Any project following GPL open-source license
The core of commercial licensing lies in how the source code is used, rather than the deployment of binary files. The developer provides flexible usage paths, ensuring both open-source spirit and legal avenues for commercial applications. The key is whether the user is willing to bear the open-source obligation, or choose to purchase a license for closed-source use.
According to the content of LICENSE and readme.md, here is a summary of the existing license definitions:
Core Points of the Existing License
Base License: GPL-3.0
VBMAN is licensed under the GNU General Public License v3.0 (GPL-3.0) open source license.
Definition of Payment Situations
1. Binary Files (Permanently Free)
Compiled binary files (DLL, EXE, etc.) of this project are permanently free with no usage restrictions.Whether for personal or commercial purposes, using the compiled DLL directly is completely free, no payment is required.
2. Source Code Usage (Scenario-Based)
| Usage Scenario | Requires Payment | Conditions |
|---|---|---|
| Personal Use | Free | Comply with GPL license (include LICENSE, open-source after modifications) |
| Commercial Use + Open Source | Free | When distributing/selling after modifying this project, must open-source the entire project's source code (GPL-compatible license) |
| Commercial Use + Closed Source | Requires Payment | Want to use source code in closed-source commercial project, not open-source your own code |
When Do You Need to Pay?
Only one condition: You want to use VBMAN source code in a closed-source commercial software and do not want to open-source your own code.
Specific scenario examples:
| Scenario | Requires Commercial License |
|---|---|
| Using VBMAN DLL to develop tools internally within the company | Free |
| Developing commercial software, directly referencing VBMAN DLL | Free |
| Modified VBMAN source code, distributing modified DLL to customers (open-source) | Free |
| Modified VBMAN source code, distributing modified DLL to customers (closed-source) | Requires Payment |
| SaaS service using VBMAN source code but closed-source deployment | Requires Payment |
Commercial License Information
For closed-source commercial licensing, please contact:
- Author: Deng Wei (邓伟)
- Website: https://a-vi.com
- Repository: https://gitcode.com/woeoio/vbman
Commercial license fees are negotiated based on specific usage scenarios and scope.
Frequently Asked Questions (FAQ)
Q1: I use VBMAN to develop internal tools at my company. Do I need to pay?
A: No. Using the DLL directly is completely free.
Q2: I modified VBMAN's source code, made it into a product and sold it to others, but I don't want to open-source it. What should I do?
A: You need to purchase a commercial license. Otherwise, it violates the GPL license.
Q3: I developed an open-source software using VBMAN. Can I charge for it?
A: Yes. The GPL license allows you to sell for a fee, but you must provide the source code to customers.
Q4: Is VBMAN2 under the same licensing policy?
A: VBMAN2 is not open-sourced, only binary files are provided, and they are permanently free to use.
Full Legal Text
For detailed terms, please refer to the LICENSE file.