Here's how I set up my Samsung Chromebook (which uses an ARM cpu) to connect to a linux (specifically Lubuntu 12.04) host over RDP using an SSH tunnel, without resorting to Developer Mode.  I suspect I'm not the only person who wants to be able to do this.

The Server
On your linux host, install the excellent X11RDP-o-Matic script.  http://scarygliders.net/2013/07/25/x11rdp-o-matic-version-3-now-released/  Note, this only works on Debian based linux, like Ubuntu.

I literally used these three steps:
1. sudo apt-get install git;
2. cd ~ && git clone https://github.com/scarygliders/X11RDP-o-Matic.git && cd X11RDP-o-Matic;
3. sudo ./X11rdp-o-matic.sh –justdoit && ./RDPsesconfig.sh;

Now I can log into my linux work PC using Microsoft's Remote Desktop Protocol.

I'm going to assume you already have an SSH server on your LAN that you can access from the internet for the purposes of tunnelling.  If not, a Google search can help you: https://www.google.ca/search?q=setting+up+an+ssh+tunnel

The Client
On your Chromebook, install the Ericom AccessToGo software.  It's free in the web store.

Hit Ctrl+Alt+T to get the Chrosh shell.  Then enter ssh to get the secure shell client.  Once there, enter the appropriate parameters:
ssh> forward 8000:x.x.x.x:3389
ssh> host y.y.y.y
ssh> user your-ssh-username
ssh> connect

where x.x.x.x is the ip-address or name of your host PC on your LAN, and y.y.y.y is the ip-address or name of your ssh server on the internet.

Finally, launch the AccessToGo app.  Enter localhost:8000 as your host, and the username and password to log into your linux desktop.  That's it!