Is there much, if any, platform specific code in there? It seems like the GUI is based on Qt5 already, which is cross-platform.
Also do you have a commercial Qt5 license? I think some components, like QtCharts, are "commercial or GPLv3", so you need to be careful with redistributing. IANAL but not having a license would mean the GPL now dictates you should release your entire program as GPLv3, which I assume is not what you want, as the source code is not available anywhere.
There is just a single module (couple hundred lines of code) that is platform specific. This can be easily ported to Linux and/or MacOS. I had a Linux version running for awhile, but just don't have the resources yet to support multiple platforms for every build.
There are two separate pieces of the project. The 'Engine' code does all the real work of managing the data and executing the queries. The 'Browser App' is used as an Admin/Demo tool which uses the Qt windowing platform. The browser just calls the engine API and makes the data display nicely in the various windows and dialogs.
I will probably open-source the browser code. I am still trying to figure out if and when I will release the engine code using one of the open source licenses. It really depends on if it can get some traction so that it is worth the effort.
Also do you have a commercial Qt5 license? I think some components, like QtCharts, are "commercial or GPLv3", so you need to be careful with redistributing. IANAL but not having a license would mean the GPL now dictates you should release your entire program as GPLv3, which I assume is not what you want, as the source code is not available anywhere.