When can I use these files?

These versions of Qt and the add-on product Qt Script for Applications (QSA) can only be used to produce Open Source software and/or run programs legally developed by others. By using this version of Qt/QSA, you agree to

• Make the complete source code of your program available to all end users
• Allow all users to re-use, modify and re-distribute the code
• Give up your right to demand compensation for re-use and re-distribution
• Add a notice to your program that it is GPL licensed when it runs

This is because the Open Source versions of our software are governed by the terms of the GNU GPL license. Using the Open Source Edition means you agree that the source of the software you write also will be published according to this license.

If you are working in a commercial environment and are required to keep the source code of your product closed, you must use the commercial version instead. Trolltech's commercial license terms do not allow you to start developing proprietary software using the Open Source edition.

Can I use the Open Source Edition to write commercial software?

Only if you plan to publish the software exclusively under the GPL.

If you plan to release a commercial product either using closed source or a mix of closed and open source licensing, you must use the commercially licensed version of Qt.

We offer a full evaluation version of Qt, including 30 days of support, to commercial evaluators. Using the evaluation version allows you to try out Qt commercially without any exposure to the GPL license. We also offer an evaluation version of Qt Script for Applications (QSA) on the same page. Please go to the Qt Evaluation Page to apply for it.

I am still unsure. Which license should I use?

If you are unsure of what license you need, then follow this simple rule of thumb: If you're Open Source, Qt is Open Source. If you're commercial, Qt is commercial. Feel free to contact us at with questions.