The UQLab software is split into a content management system (UQLabCore) which is closed source and subjected to licensing, and a set of scientific modules (UQLabModules) which are available open source (BSD-3-Clause). All scientific content of UQLab is provided by the UQLabModules; No computational tasks nor algorithms are handled by UQLabCore.
The license for UQLabCore is free for members of academic institutions (universities, public research institutes, etc.) having a valid email address with an educational domain. If you are not associated with an academic institution or do not have a valid academic email address, you can get a 30-day fully-functional demo license by contacting the Developer Team directly. Beyond this demo period, you can purchase a non-academic license to ETH Zurich.
You can always get the open-source code of UQLabModules through the UQLab website.
UQLabModules is not a standalone software. To function properly as an uncertainty quantification framework, UQLab requires both UQLabCore and UQLabModules. UQLabModules makes use of the advanced API provided by UQLabCore to function properly.