I was looking at the QT-Digia site, and I found that they really try not to get people to use open source. So i thought that it would be a good game to see how many examples we can find of companies trying to downgrade open source projects or licenses.
Here's what Digia say about GPL:
LGPL and GPL are complex licenses that contain many obligations and restrictions you must abide with. Always consult an experienced lawyer before choosing these licenses for your project.
Is it really that dangerous to develop under LGPL and GPL? On Linux, most things are GPL so I find this really weird.
No, it is not "dangerous" (atleast not any more dangerous than software development in general) to develop under LGPL or GPL, There are however things you need to keep in mind if you're using LGPL licensed libraries in a proprietary project. (The GPL is quite simple, if you use any GPL licensed code then everything that touches that code has to be released under either the GPL or a license that grants the atleast same rights and doesn't add any additional restrictions for the end user).
As far as complexity goes both the GPL and the LGPL are reasonably straightforward compared to pretty much every single proprietary license i've seen thus far so i don't think the need to consult a lawyer is any greater with LGPL licensed libraries(Its always a good idea to consult a lawyer if you intend to distribute software in countries such as the US where the patent minefields are a big problem) unless you intend to find a way around the restrictions of the licenses.
Compared to other less restrictive opensource licenses however the GPL and LGPL are fairly complex and for proprietary development (most games are proprietary since it is very difficult to find a good businessmodel for a free software game) other licenses tend to fit much better.
When it comes to games the biggest problem with the LGPL(and GPL if you're making an opensource game) is that your end users has to be able to upgrade / replace / modify the LGPL/GPL licensed portions, on iOS and consoles they cannot do this due to the restricted nature of the platform and thus you cannot use other peoples LGPL/GPL licensd code (v3 atleast, v2 might possibly allow it but trying to take advantage of loopholes is always risky) at all on those platforms (unless you have the original authors permission), You might also have problems with copyprotection systems since they'd have to allow the use of modified libraries.