I have seen so many people search for totally free vps servers. Why do you really need a free vps server ? giving away a free shared hosting account is not hard. But giving a free vps is not that easy. Specially if it's a proper vps with at least one dedicated IP address. These IPs cost around $0.50 - $1 per one monthly. Someone has to pay that.
This is one reason why it's really hard to run a free vps service. each vps cost at least $1 since you have to pay for IP addresses. So far I have seen only one successful free vps providers. Host1free is pretty much useless since they rarely pick one of to give a vps and even that's just 128MB RAM node which you can use for anything but testing things. Also there are fake free vps providers like freevps.me and other sites like 5Jelly.
If you are searching for a free vps then you should first thing about why do you need a free vps and do you really need a free vps. If you have a web site which can't run in a usual shared hosting account that means you get reasonable number of visitors per month. Then you should able to use ad network and try to earn some money from your site and buy a small cheap VPS server. You can find a decent un-manage one for around $5 per month or around $20 per year. I'm talking about a VPS with at least 1GB RAM and really good uptime. You will need to learn all about how to handle it from installations to security but you can learn all these stuff from forums. This is the best thing because having a free vps doesn't mean it would sort all your problems.
There are only 3 other reasonable things I can see why someone need a free vps. You might be a developer who's creating a new web related software. You need a server to test and learn about servers. Or you are looking for vps so you can create a game server.