Ask HN: A site that let you setup a virtual linux machine, for sandboxing?

I remember seeing a site on Hacker News earlier this year where you could set up a virtual linux machine running on one of their servers, and choose from a gallery of pre-configured options, like various OSs, and setups for specific purposes.

As far as I remember, you were allowed full usage, to a limited capacity, for free, and then after there were paid plans. It might have been something like 3 low-end machines for free, and then it started costing money.

Anybody remember this, or know what it's called?