Looking for citrix alternative

[WLD-web]

Hi everyone, i'm sorry for my bad english.

This is my problem:

i'm using windows server and my clients using different OS (Windows, Linux, Mac, Phones... etc) and i want them to access the apps through the internet using just a browser. We were using citrix but they cut us off and i don't know why. Now i'm looking for a free alternative.

I hope this was helpful