And actually, it's the resources that are free (CPU, memory, network) and you're allowed to split them up into multiple VMs if you want to.

One of my VMs had an uptime of more than 1050 days before the infrastructure rebooted it, so in terms of availability they've certainly surprised me.

The only downside I've come across with Oracle Free is that the 'best' regions are typically full. I ended up provisioning my free VMs in another region/country and it works fine.

I suppose another downside (if you want to view it this way) is they will delete idle unused free VMs after a certain time period. You have to add a credit card to your account to "upgrade" your account and run free resource indefinitely. While you're not charged for anything, it makes me nervous forking over a CC number to Oracle.