From the WSJT-X developers:
Anyone is welcome to build WSJT-X from source code, and use the results on the air. But please DO NOT post your pre-built binaries for others to download. This causes needless support problems for us. We have no way of knowing exactly what you did. And if all you post is some sort of binary, you're violating our GPL license.
Soon enough, when desirable new features have been added to the program, we build and post "release candidate" installation packages that everyone can use. Such a time is not far off.
In the meantime, please "build your own", or be patient.
-- 73, Joe, K1JT
You must monitor the wsjt-devel list if you are building from sources as there may be issues with the latest sources, due to work in progress, that makes the build products unsuitable for use on air. Keeping up with development status is non-optional for those that build from sources, it is part of the deal we offer allowing anyone to do so.
So you want to build from source, it's not difficult at all:
For Microsoft Windows users, follow the steps on this site.
To see what is the current version, and keep up with the changes, see this site.