These systems are either new, or are experimental or beta-release systems and as such may not have the popular and immediate appeal of systems in other tiers.

You should also realize that, especially if you are not paying for the system, the system authors have no "responsibility" to the community to update their program. There was once a nasty stir on raif in which a poster ordered Graham Nelson, who had been unable to read the newsgroup for a while for various reasons, to update Inform. Graham and the other authors have put a lot of hard work into their systems, and probably will continue to do so. But if they wanted to stop, they could. (After many messages asserting that point were posted, the thread died down. This was shortly followed by a new version of Inform.)

A NOTE ON LICENSING: Games written with some authoring systems, notably Hugo, may not be distributed for money (shareware or commercial) without the system author's express consent. You should always read and abide by any and all licensing details relating to the system which you choose. If you do not like the licensing arrangements, use a different system. Of course, system authors are (usually) good human beings, and will probably say yes.