This is the *(topic) for machines you shouldn't use, least you'll become the hostage of the vendors who lock you and whoever else you will communicate with you into their technology.

However attractive a proprietary technology may appear, it shouldn't be used as a means of communication.

Happily, no one owns the english language.

Of course, it is good to know what proprietary VMs exist or have existed, to be aware of their advantages and shortcomings, which is why they are listed here.

/("proprietary VM" :attribute :topic :match :exact)