Qt is available under two different flavors and licenses—commercial and open-source (General Public License (GPL) and/or Lesser General Public License (LGPL)). They differ both in terms of features that are included and legal requirements. It is important to understand the differences.
Legally, the open-source version of Qt brings its own set of limitations. While cost is not an object, complying with open-source preconditions, dealing with product liability, intellectual property, warranties, and source code disclosures, may make it very difficult, if not impossible, to use the open-source version in an embedded product. The commercial license does not have as many restrictions.
If you have a question about what is appropriate for your project, work with your company's legal, risk management, and intellectual property teams.
Beyond the...
