>If someone makes a piece of software available for free, even if it's just a binary, then it remains free unless or until the company revokes that status.
This is not in accordance with copyright law.
Corel granted permission to get copies from Corel. If you already have a copy from Corel, it remains free. But this isn't GPL; you don't have permission to make further copies of one of the free copies. If you get a copy from one of the third parties that still has it available for download, you're violating copyright, even if the third party themselves got their own copy for free.
Other companies distributed the free version, too. It was bundled with at least one print book. It was included with old versions of both SUSE Linux and Mandrake Linux. It was sold, on CD, by various long-gone vendors.
It was available from multiple other sources than Corel, and has been since the early days.
I entirely see where you're coming from, and I've added a paragraph clarifying its status to my blog post. However, given its wide distribution over more than 20 years, which Corel has never seeked to stop, I think it is fair. This is not "abandonware". Corel made this one version free of charge and has never rescinded that.
This is not in accordance with copyright law.
Corel granted permission to get copies from Corel. If you already have a copy from Corel, it remains free. But this isn't GPL; you don't have permission to make further copies of one of the free copies. If you get a copy from one of the third parties that still has it available for download, you're violating copyright, even if the third party themselves got their own copy for free.