What is this? See the short text at http://www.wormbook.org/wbg/articles/volume-18-number-3/jflux-%E2%80%93-a-platform-for-flow-cytometry-with-focus-on-the-copas-biosorter/
The software is still in development. Interested users are best off download it from the repository. For instructions, see https://sourceforge.net/scm/?type=git&group_id=376945 (you will need to know how to at least compile Java programs). I recommend Eclipse with EGIT for development.
Since there isn’t much of a website yet, you might want to go to the project page instead.