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randomguy
8th June 2009, 03:59
So let me premise this by saying i am a beginner to toolkits like QT and license stuff in general.

Like i know what the GPL is and that it basically says that someone can modify code without seeking permission. And the person who writes it has to release the code.

but it seems like the current version of QT also allows for Limited GPL apps. not really sure what the distinction is. It also allows for commercial licensing (for about $3.5k). considering im aiming for book money a commercial license isnt what im looking for.

i would like to work on a small puzzle game and sell it for like $1. I dont understand if i would be able to make proprietary applications with QT. Im fine with releasing GUI code i guess but would like some backend stuff to be closed source (so like the GUI registration asks for a serial number and when they click ok it will call a proprietary C++ function that determines if the key is valid. i wouldnt want to release parts of the code that do that if i want to sell the program). but then the question goes to whether you can ship opensource binaries and closed source binaries together with the same installer (for windows users) or tarbell (for linx users).

i'm sorry if this is really obvious to everyone else but it honestly confuses me a lot more than actual coding and development. im drawn to QT because it seems like a really good toolkit and has support for advanced things like OpenGL. Even if i cant do this little pet project in QT ill still learn it more and probably work on some open source stuff but it would be nice to be able to use the framework to do what i want without having to pay 10 times what i expect to make for a license thing.

thanks for the information.

nish
8th June 2009, 04:19
LGPL means that u can make and distribute closed source commercial applications as long as u are linking to the Qt library dynamically. In short:

1. No changes should be done to the Qt Library code
2. Could not link statically to Qt.
3. No need to release any of your code.
4. No need to pay anything to Qt Software
5. Charge your app for $1 millon.