The first suggested Java link on https://www.b4x.com/b4j.html fails when the download reaches about 39MB out of the 200+ supposedly in the zip file.
Repeatedly tried yesterday and today with same result.
Absolutely will not download in latest Firefox.
I finally got it on 3rd try in Edge.
Earlier Edge tries produced an odd small file in the form "Unconfirmed xxxx.crdownload," where xxxx is some number (error number?)
I am running completely up-to-date Win 10 64-bit and have not seen such download issues elsewhere.