Unfortunately, there is no one-size-fits-all answer to this question. Possible—and only possible—answers are:

•   Do you get your application software plus A-Shell from a dealer / reseller / consultant? Ask them about which version is right for you.

•   Do you get A-Shell directly from MicroSabio? You likely should have the latest stable version.

•   Are you a "bleeding edge" user or developer who always wants the latest version? Get the very latest available version.

The best source of information about versions—latest, stable, historical—is the MicroSabio webpage that deals with that subject. Click on this link http://microsabio.com/downloads/ to go directly to that page.

Remember that A-Shell is being continually updated by the developers. In other words, the target is always moving and today's "latest stable" version might be—will certainly be, at some point—tomorrow's historical version. If you are the person in change of keeping your copy of A-Shell or ATE up to date, then you should probably be updating approximately once a year.

Also note that it is up to you, the person installing the update, to know what you are doing! You need to determine if the update is required or recommended, and what problems you might encounter during the process. The normal answers are yes (recommended) and none (expected problems), but you are nonetheless responsible for the process. Caution is advised.