Create a integrated GUI, replacing what we have
allows creating amazing GUIs that are portable. We currently have separate GUIs (they are different binaries that run the command line main program) for each supported platform. The job is to create a GUI that is part of the current binary and that works in Windows / Linux / OSX.
The library above is a suggestion. It may or may not be exactly what we need, even though it's really promising. It's your job to do the research (this should be part of your proposal, i.e. you need to tell us what library you plan to use), and come up with a good plan.
We will assist with integration and you probably can get away without going too deep into the current code. However, when it comes to the GUI itself, you are in the driver's seat. We haven't used this library ourselves so we're there for moral support and general peer support (when you run into problems we'll look into them together, but we won't have guru-level answers ready).
Also check this out.